2556021536761 has 16 divisors (see below), whose sum is σ = 3202904453760. Its totient is φ = 1981594903680.

The previous prime is 2556021536759. The next prime is 2556021536773. The reversal of 2556021536761 is 1676351206552.

It is not a de Polignac number, because 2556021536761 - 2¹ = 2556021536759 is a prime.

It is a super-2 number, since 2×2556021536761² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2556021536261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84236316 + ... + 84266653.

It is an arithmetic number, because the mean of its divisors is an integer number (200181528360).

Almost surely, 2^{2556021536761} is an apocalyptic number.

It is an amenable number.

2556021536761 is a deficient number, since it is larger than the sum of its proper divisors (646882916999).

2556021536761 is a wasteful number, since it uses less digits than its factorization.

2556021536761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168503184.

The product of its (nonzero) digits is 2268000, while the sum is 49.

The spelling of 2556021536761 in words is "two trillion, five hundred fifty-six billion, twenty-one million, five hundred thirty-six thousand, seven hundred sixty-one".