2564641 has 4 divisors (see below), whose sum is σ = 2569284. Its totient is φ = 2560000.

The previous prime is 2564633. The next prime is 2564651. The reversal of 2564641 is 1464652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1134225 + 1430416 = 1065^2 + 1196^2 .

It is a 4-Lehmer number, since φ(2564641) divides (2564641-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 2564641 - 2³ = 2564633 is a prime.

It is a Duffinian 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, 1360 + ... + 2641.

It is an arithmetic number, because the mean of its divisors is an integer number (642321).

2^2564641 is an apocalyptic number.

It is an amenable number.

2564641 is a deficient number, since it is larger than the sum of its proper divisors (4643).

2564641 is an equidigital number, since it uses as much as digits as its factorization.

2564641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4642.

The product of its digits is 5760, while the sum is 28.

The square root of 2564641 is about 1601.4496557807. The cubic root of 2564641 is about 136.8806924789.

It can be divided in two parts, 2564 and 641, that multiplied together give a square (1643524 = 1282²).

The spelling of 2564641 in words is "two million, five hundred sixty-four thousand, six hundred forty-one".