2564512721 has 2 divisors, whose sum is σ = 2564512722. Its totient is φ = 2564512720.

The previous prime is 2564512697. The next prime is 2564512759. The reversal of 2564512721 is 1272154652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2269188496 + 295324225 = 47636^2 + 17185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2564512721 is a prime.

It is not a weakly prime, because it can be changed into another prime (2564512771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282256360 + 1282256361.

It is an arithmetic number, because the mean of its divisors is an integer number (1282256361).

Almost surely, 2^2564512721 is an apocalyptic number.

It is an amenable number.

2564512721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564512721 is an equidigital number, since it uses as much as digits as its factorization.

2564512721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 35.

The square root of 2564512721 is about 50641.0181670945. The cubic root of 2564512721 is about 1368.7841026066.

The spelling of 2564512721 in words is "two billion, five hundred sixty-four million, five hundred twelve thousand, seven hundred twenty-one".