640642372 has 12 divisors (see below), whose sum is σ = 1136915136. Its totient is φ = 315809480.

The previous prime is 640642369. The next prime is 640642411. The reversal of 640642372 is 273246046.

640642372 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-4 number, since 4×640642372⁴ (a number of 36 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1127608 + ... + 1128175.

It is an arithmetic number, because the mean of its divisors is an integer number (94742928).

Almost surely, 2^640642372 is an apocalyptic number.

It is an amenable number.

640642372 is a deficient number, since it is larger than the sum of its proper divisors (496272764).

640642372 is a wasteful number, since it uses less digits than its factorization.

640642372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255858 (or 2255856 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 640642372 is about 25310.9140885903. The cubic root of 640642372 is about 862.0621022113.

The spelling of 640642372 in words is "six hundred forty million, six hundred forty-two thousand, three hundred seventy-two".