2151220 has 24 divisors (see below), whose sum is σ = 4674600. Its totient is φ = 830592.

The previous prime is 2151211. The next prime is 2151221. The reversal of 2151220 is 221512.

2151220 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 94864 + 2056356 = 308^2 + 1434^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2151220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1275 + ... + 2434.

It is an arithmetic number, because the mean of its divisors is an integer number (194775).

2^2151220 is an apocalyptic number.

2151220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2151220 is an abundant number, since it is smaller than the sum of its proper divisors (2523380).

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

2151220 is a wasteful number, since it uses less digits than its factorization.

2151220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3747 (or 3745 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 2151220 is about 1466.7037874090. The cubic root of 2151220 is about 129.0906959895.

Adding to 2151220 its reverse (221512), we get a palindrome (2372732).

The spelling of 2151220 in words is "two million, one hundred fifty-one thousand, two hundred twenty".