2564649 has 24 divisors (see below), whose sum is σ = 3972320. Its totient is φ = 1634472.

The previous prime is 2564633. The next prime is 2564651. The reversal of 2564649 is 9464652.

2564649 is a `hidden beast` number, since 2 + 5 + 6 + 4 + 649 = 666.

It is not a de Polignac number, because 2564649 - 2⁴ = 2564633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2564609) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54544 + ... + 54590.

2^2564649 is an apocalyptic number.

It is an amenable number.

2564649 is a deficient number, since it is larger than the sum of its proper divisors (1407671).

2564649 is an equidigital number, since it uses as much as digits as its factorization.

2564649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 93 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 2564649 is about 1601.4521535157. The cubic root of 2564649 is about 136.8808348047.

The spelling of 2564649 in words is "two million, five hundred sixty-four thousand, six hundred forty-nine".