2564697649 has 2 divisors, whose sum is σ = 2564697650. Its totient is φ = 2564697648.

The previous prime is 2564697647. The next prime is 2564697683. The reversal of 2564697649 is 9467964652.

2564697649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1510721424 + 1053976225 = 38868^2 + 32465^2 .

It is a cyclic number.

It is not a de Polignac number, because 2564697649 - 2¹ = 2564697647 is a prime.

It is a super-2 number, since 2×2564697649² = 13155348061572254402, which contains 22 as substring.

Together with 2564697647, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2564697593 and 2564697602.

It is not a weakly prime, because it can be changed into another prime (2564697647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282348824 + 1282348825.

It is an arithmetic number, because the mean of its divisors is an integer number (1282348825).

Almost surely, 2^2564697649 is an apocalyptic number.

It is an amenable number.

2564697649 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564697649 is an equidigital number, since it uses as much as digits as its factorization.

2564697649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19595520, while the sum is 58.

The square root of 2564697649 is about 50642.8440058415. The cubic root of 2564697649 is about 1368.8170029987.

The spelling of 2564697649 in words is "two billion, five hundred sixty-four million, six hundred ninety-seven thousand, six hundred forty-nine".