2155560 has 128 divisors (see below), whose sum is σ = 7464960. Its totient is φ = 492800.

The previous prime is 2155519. The next prime is 2155579. The reversal of 2155560 is 655512.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2155560.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30325 + ... + 30395.

It is an arithmetic number, because the mean of its divisors is an integer number (58320).

2^2155560 is an apocalyptic number.

2155560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2155560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3732480).

2155560 is an abundant number, since it is smaller than the sum of its proper divisors (5309400).

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

2155560 is a wasteful number, since it uses less digits than its factorization.

2155560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 2155560 is about 1468.1825499576. The cubic root of 2155560 is about 129.1774494409.

It can be divided in two parts, 215 and 5560, that added together give a palindrome (5775).

The spelling of 2155560 in words is "two million, one hundred fifty-five thousand, five hundred sixty".