640018958 has 8 divisors (see below), whose sum is σ = 1016500752. Its totient is φ = 301185376.

The previous prime is 640018949. The next prime is 640018969. The reversal of 640018958 is 859810046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

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, 9412010 + ... + 9412077.

It is an arithmetic number, because the mean of its divisors is an integer number (127062594).

Almost surely, 2^640018958 is an apocalyptic number.

640018958 is a deficient number, since it is larger than the sum of its proper divisors (376481794).

640018958 is a wasteful number, since it uses less digits than its factorization.

640018958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18824106.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 640018958 is about 25298.5959689466. The cubic root of 640018958 is about 861.7823850481.

The spelling of 640018958 in words is "six hundred forty million, eighteen thousand, nine hundred fifty-eight".