664734725 has 6 divisors (see below), whose sum is σ = 824271090. Its totient is φ = 531787760.

The previous prime is 664734713. The next prime is 664734727. The reversal of 664734725 is 527437466.

It can be written as a sum of positive squares in 3 ways, for example, as 229441 + 664505284 = 479^2 + 25778^2 .

It is not a de Polignac number, because 664734725 - 2⁴ = 664734709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664734727) 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, 13294670 + ... + 13294719.

It is an arithmetic number, because the mean of its divisors is an integer number (137378515).

Almost surely, 2^664734725 is an apocalyptic number.

It is an amenable number.

664734725 is a deficient number, since it is larger than the sum of its proper divisors (159536365).

664734725 is a wasteful number, since it uses less digits than its factorization.

664734725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26589399 (or 26589394 counting only the distinct ones).

The product of its digits is 846720, while the sum is 44.

The square root of 664734725 is about 25782.4499417724. The cubic root of 664734725 is about 872.7357950343.

The spelling of 664734725 in words is "six hundred sixty-four million, seven hundred thirty-four thousand, seven hundred twenty-five".