664817680725 has 192 divisors, whose sum is σ = 1270106707968. Its totient is φ = 303937920000.

The previous prime is 664817680699. The next prime is 664817680727. The reversal of 664817680725 is 527086718466.

It is not a de Polignac number, because 664817680725 - 2¹¹ = 664817678677 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664817680727) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 134277000 + ... + 134281950.

It is an arithmetic number, because the mean of its divisors is an integer number (6615139104).

Almost surely, 2^664817680725 is an apocalyptic number.

It is an amenable number.

664817680725 is a deficient number, since it is larger than the sum of its proper divisors (605289027243).

664817680725 is a wasteful number, since it uses less digits than its factorization.

664817680725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5148 (or 5143 counting only the distinct ones).

The product of its (nonzero) digits is 27095040, while the sum is 60.

The spelling of 664817680725 in words is "six hundred sixty-four billion, eight hundred seventeen million, six hundred eighty thousand, seven hundred twenty-five".