640625177 has 4 divisors (see below), whose sum is σ = 640676736. Its totient is φ = 640573620.

The previous prime is 640625171. The next prime is 640625197. The reversal of 640625177 is 771526046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 640625177 - 2²⁶ = 573516313 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640625177.

It is not an unprimeable number, because it can be changed into a prime (640625171) 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, 5552 + ... + 36222.

It is an arithmetic number, because the mean of its divisors is an integer number (160169184).

Almost surely, 2^640625177 is an apocalyptic number.

It is an amenable number.

640625177 is a deficient number, since it is larger than the sum of its proper divisors (51559).

640625177 is a wasteful number, since it uses less digits than its factorization.

640625177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51558.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 640625177 is about 25310.5744107083. The cubic root of 640625177 is about 862.0543894888.

The spelling of 640625177 in words is "six hundred forty million, six hundred twenty-five thousand, one hundred seventy-seven".