2151621533256 has 64 divisors (see below), whose sum is σ = 5793009196800. Its totient is φ = 662016595968.

The previous prime is 2151621533233. The next prime is 2151621533261. The reversal of 2151621533256 is 6523351261512.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12006360 + ... + 12184248.

It is an arithmetic number, because the mean of its divisors is an integer number (90515768700).

Almost surely, 2^{2151621533256} is an apocalyptic number.

2151621533256 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

2151621533256 is an abundant number, since it is smaller than the sum of its proper divisors (3641387663544).

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

2151621533256 is a wasteful number, since it uses less digits than its factorization.

2151621533256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216678 (or 216674 counting only the distinct ones).

The product of its digits is 324000, while the sum is 42.

Adding to 2151621533256 its reverse (6523351261512), we get a palindrome (8674972794768).

The spelling of 2151621533256 in words is "two trillion, one hundred fifty-one billion, six hundred twenty-one million, five hundred thirty-three thousand, two hundred fifty-six".