646100400 has 120 divisors (see below), whose sum is σ = 2257873344. Its totient is φ = 156627200.

The previous prime is 646100387. The next prime is 646100431. The reversal of 646100400 is 4001646.

646100400 = 469² + 470² + ... + 1268².

It is a tau number, because it is divible by the number of its divisors (120).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11274 + ... + 37673.

Almost surely, 2^646100400 is an apocalyptic number.

646100400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646100400 is an abundant number, since it is smaller than the sum of its proper divisors (1611772944).

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

646100400 is a wasteful number, since it uses less digits than its factorization.

646100400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48979 (or 48968 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 646100400 is about 25418.5050701256. The cubic root of 646100400 is about 864.5033289819.

The spelling of 646100400 in words is "six hundred forty-six million, one hundred thousand, four hundred".