2156817133128 has 32 divisors (see below), whose sum is σ = 6162334666560. Its totient is φ = 616233466560.

The previous prime is 2156817133111. The next prime is 2156817133129. The reversal of 2156817133128 is 8213317186512.

It is not an unprimeable number, because it can be changed into a prime (2156817133129) 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, 6419098443 + ... + 6419098778.

It is an arithmetic number, because the mean of its divisors is an integer number (192572958330).

Almost surely, 2^{2156817133128} is an apocalyptic number.

2156817133128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

2156817133128 is an abundant number, since it is smaller than the sum of its proper divisors (4005517533432).

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

2156817133128 is a wasteful number, since it uses less digits than its factorization.

2156817133128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12838197237 (or 12838197233 counting only the distinct ones).

The product of its digits is 483840, while the sum is 48.

The spelling of 2156817133128 in words is "two trillion, one hundred fifty-six billion, eight hundred seventeen million, one hundred thirty-three thousand, one hundred twenty-eight".