2564691 has 4 divisors (see below), whose sum is σ = 3419592. Its totient is φ = 1709792.

The previous prime is 2564669. The next prime is 2564701. The reversal of 2564691 is 1964652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2564691 - 2¹⁰ = 2563667 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (2564621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 427446 + ... + 427451.

It is an arithmetic number, because the mean of its divisors is an integer number (854898).

2^2564691 is an apocalyptic number.

2564691 is a deficient number, since it is larger than the sum of its proper divisors (854901).

2564691 is an equidigital number, since it uses as much as digits as its factorization.

2564691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854900.

The product of its digits is 12960, while the sum is 33.

The square root of 2564691 is about 1601.4652665606. The cubic root of 2564691 is about 136.8815820108.

The spelling of 2564691 in words is "two million, five hundred sixty-four thousand, six hundred ninety-one".