646105664 has 14 divisors (see below), whose sum is σ = 1282116054. Its totient is φ = 323052800.

The previous prime is 646105661. The next prime is 646105667. The reversal of 646105664 is 466501646.

It is an interprime number because it is at equal distance from previous prime (646105661) and next prime (646105667).

It can be written as a sum of positive squares in only one way, i.e., 637057600 + 9048064 = 25240^2 + 3008^2 .

It is not an unprimeable number, because it can be changed into a prime (646105661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5047637 + ... + 5047764.

Almost surely, 2^646105664 is an apocalyptic number.

646105664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

646105664 is a deficient number, since it is larger than the sum of its proper divisors (636010390).

646105664 is a wasteful number, since it uses less digits than its factorization.

646105664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10095413 (or 10095403 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 646105664 is about 25418.6086165234. The cubic root of 646105664 is about 864.5056767765.

The spelling of 646105664 in words is "six hundred forty-six million, one hundred five thousand, six hundred sixty-four".