643506610 has 64 divisors (see below), whose sum is σ = 1282355712. Its totient is φ = 231469056.

The previous prime is 643506601. The next prime is 643506631. The reversal of 643506610 is 16605346.

It is a super-2 number, since 2×643506610² = 828201514227384200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 342634 + ... + 344506.

It is an arithmetic number, because the mean of its divisors is an integer number (20036808).

Almost surely, 2^643506610 is an apocalyptic number.

643506610 is a deficient number, since it is larger than the sum of its proper divisors (638849102).

643506610 is a wasteful number, since it uses less digits than its factorization.

643506610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1987.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 643506610 is about 25367.4320734283. The cubic root of 643506610 is about 863.3449190053.

The spelling of 643506610 in words is "six hundred forty-three million, five hundred six thousand, six hundred ten".