664811025 has 12 divisors (see below), whose sum is σ = 1099154352. Its totient is φ = 354565840.

The previous prime is 664810981. The next prime is 664811029. The reversal of 664811025 is 520118466.

It is not a de Polignac number, because 664811025 - 2⁶ = 664810961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (664811029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4431999 + ... + 4432148.

It is an arithmetic number, because the mean of its divisors is an integer number (91596196).

Almost surely, 2^664811025 is an apocalyptic number.

It is an amenable number.

664811025 is a deficient number, since it is larger than the sum of its proper divisors (434343327).

664811025 is a wasteful number, since it uses less digits than its factorization.

664811025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8864160 (or 8864155 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 664811025 is about 25783.9295880205. The cubic root of 664811025 is about 872.7691853934.

The spelling of 664811025 in words is "six hundred sixty-four million, eight hundred eleven thousand, twenty-five".