2565609988 has 18 divisors (see below), whose sum is σ = 4515557774. Its totient is φ = 1275458304.

The previous prime is 2565609913. The next prime is 2565609989. The reversal of 2565609988 is 8899065652.

It can be written as a sum of positive squares in only one way, i.e., 1914237504 + 651372484 = 43752^2 + 25522^2 .

It is a super-2 number, since 2×2565609988² = 13164709221050720288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2565609989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1406445 + ... + 1408267.

Almost surely, 2^2565609988 is an apocalyptic number.

It is an amenable number.

2565609988 is a deficient number, since it is larger than the sum of its proper divisors (1949947786).

2565609988 is an equidigital number, since it uses as much as digits as its factorization.

2565609988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3843 (or 2018 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 58.

The square root of 2565609988 is about 50651.8507855340. The cubic root of 2565609988 is about 1368.9792933547.

The spelling of 2565609988 in words is "two billion, five hundred sixty-five million, six hundred nine thousand, nine hundred eighty-eight".