2564644465 has 4 divisors (see below), whose sum is σ = 3077573364. Its totient is φ = 2051715568.

The previous prime is 2564644451. The next prime is 2564644469. The reversal of 2564644465 is 5644464652.

It is a happy number.

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 1557407296 + 1007237169 = 39464^2 + 31737^2 .

It is a cyclic number.

It is not a de Polignac number, because 2564644465 - 2⁷ = 2564644337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2564644469) 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, 256464442 + ... + 256464451.

It is an arithmetic number, because the mean of its divisors is an integer number (769393341).

Almost surely, 2^2564644465 is an apocalyptic number.

It is an amenable number.

2564644465 is a deficient number, since it is larger than the sum of its proper divisors (512928899).

2564644465 is an equidigital number, since it uses as much as digits as its factorization.

2564644465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512928898.

The product of its digits is 2764800, while the sum is 46.

The square root of 2564644465 is about 50642.3189141256. The cubic root of 2564644465 is about 1368.8075412380.

The spelling of 2564644465 in words is "two billion, five hundred sixty-four million, six hundred forty-four thousand, four hundred sixty-five".