2121915756 has 12 divisors (see below), whose sum is σ = 4951136792. Its totient is φ = 707305248.

The previous prime is 2121915751. The next prime is 2121915779. The reversal of 2121915756 is 6575191212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×2121915756² = 9005052951122103072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2121915751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88413145 + ... + 88413168.

Almost surely, 2^2121915756 is an apocalyptic number.

It is an amenable number.

2121915756 is an abundant number, since it is smaller than the sum of its proper divisors (2829221036).

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

2121915756 is a wasteful number, since it uses less digits than its factorization.

2121915756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176826320 (or 176826318 counting only the distinct ones).

The product of its digits is 37800, while the sum is 39.

The square root of 2121915756 is about 46064.2568158871. The cubic root of 2121915756 is about 1285.0184973138.

The spelling of 2121915756 in words is "two billion, one hundred twenty-one million, nine hundred fifteen thousand, seven hundred fifty-six".