646690140866 has 64 divisors (see below), whose sum is σ = 1248654680064. Its totient is φ = 243781228800.

The previous prime is 646690140821. The next prime is 646690140883. The reversal of 646690140866 is 668041096646.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32152385 + ... + 32172491.

It is an arithmetic number, because the mean of its divisors is an integer number (19510229376).

Almost surely, 2^646690140866 is an apocalyptic number.

646690140866 is a deficient number, since it is larger than the sum of its proper divisors (601964539198).

646690140866 is a wasteful number, since it uses less digits than its factorization.

646690140866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26895.

The product of its (nonzero) digits is 8957952, while the sum is 56.

The spelling of 646690140866 in words is "six hundred forty-six billion, six hundred ninety million, one hundred forty thousand, eight hundred sixty-six".