2564742521 has 16 divisors (see below), whose sum is σ = 2832599040. Its totient is φ = 2302836480.

The previous prime is 2564742517. The next prime is 2564742563. The reversal of 2564742521 is 1252474652.

It is a cyclic number.

It is not a de Polignac number, because 2564742521 - 2² = 2564742517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2564742511) 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, 315905 + ... + 323921.

It is an arithmetic number, because the mean of its divisors is an integer number (177037440).

Almost surely, 2^2564742521 is an apocalyptic number.

It is an amenable number.

2564742521 is a deficient number, since it is larger than the sum of its proper divisors (267856519).

2564742521 is a wasteful number, since it uses less digits than its factorization.

2564742521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8384.

The product of its digits is 134400, while the sum is 38.

The square root of 2564742521 is about 50643.2870279961. The cubic root of 2564742521 is about 1368.8249859018.

The spelling of 2564742521 in words is "two billion, five hundred sixty-four million, seven hundred forty-two thousand, five hundred twenty-one".