2156520080561 has 12 divisors (see below), whose sum is σ = 2736659991600. Its totient is φ = 1680405257160.

The previous prime is 2156520080551. The next prime is 2156520080623. The reversal of 2156520080561 is 1650800256512.

It is not a de Polignac number, because 2156520080561 - 2²² = 2156515886257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156520080551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2000481911 + ... + 2000482988.

It is an arithmetic number, because the mean of its divisors is an integer number (228054999300).

Almost surely, 2^{2156520080561} is an apocalyptic number.

It is an amenable number.

2156520080561 is a deficient number, since it is larger than the sum of its proper divisors (580139911039).

2156520080561 is a wasteful number, since it uses less digits than its factorization.

2156520080561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4000964924 (or 4000964917 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 41.

The spelling of 2156520080561 in words is "two trillion, one hundred fifty-six billion, five hundred twenty million, eighty thousand, five hundred sixty-one".