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2156 = 227211

2156 has 18 divisors (see below), whose sum is σ = 4788. Its totient is φ = 840.

The previous prime is 2153. The next prime is 2161. The reversal of 2156 is 6512.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an Ulam number.

Its product of digits (60) is a multiple of the sum of its prime divisors (20).

It is a nialpdrome in base 5, base 7 and base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 2156.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 2156.

It is not an unprimeable number, because it can be changed into a prime (2153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 191 + ... + 201.

It is an arithmetic number, because the mean of its divisors is an integer number (266).

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2394).

2156 is an abundant number, since it is smaller than the sum of its proper divisors (2632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2156 is a wasteful number, since it uses less digits than its factorization.

2156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29 (or 20 counting only the distinct ones).

The product of its digits is 60, while the sum is 14.

The square root of 2156 is about 46.4327470650. The cubic root of 2156 is about 12.9186238218.

Adding to 2156 its reverse (6512), we get a palindrome (8668).

Subtracting 2156 from its reverse (6512), we obtain a square (4356 = 662).

It can be divided in two parts, 21 and 56, that multiplied together give a triangular number (1176 = T48).

The spelling of 2156 in words is "two thousand, one hundred fifty-six".

Divisors: 1 2 4 7 11 14 22 28 44 49 77 98 154 196 308 539 1078 2156