640974858 has 8 divisors (see below), whose sum is σ = 1281949728. Its totient is φ = 213658284.

The previous prime is 640974847. The next prime is 640974869. The reversal of 640974858 is 858479046.

It is an interprime number because it is at equal distance from previous prime (640974847) and next prime (640974869).

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

640974858 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 640974858.

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, 53414566 + ... + 53414577.

It is an arithmetic number, because the mean of its divisors is an integer number (160243716).

Almost surely, 2^640974858 is an apocalyptic number.

640974858 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640974858 is a wasteful number, since it uses less digits than its factorization.

640974858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106829148.

The product of its (nonzero) digits is 1935360, while the sum is 51.

The square root of 640974858 is about 25317.4812728281. The cubic root of 640974858 is about 862.2112098477.

The spelling of 640974858 in words is "six hundred forty million, nine hundred seventy-four thousand, eight hundred fifty-eight".