646986975408 has 60 divisors (see below), whose sum is σ = 1889389510320. Its totient is φ = 206285701248.

The previous prime is 646986975403. The next prime is 646986975449. The reversal of 646986975408 is 804579689646.

646986975408 is a `hidden beast` number, since 6 + 4 + 6 + 98 + 69 + 75 + 408 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (646986975403) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 97669843 + ... + 97676466.

It is an arithmetic number, because the mean of its divisors is an integer number (31489825172).

Almost surely, 2^646986975408 is an apocalyptic number.

It is an amenable number.

646986975408 is an abundant number, since it is smaller than the sum of its proper divisors (1242402534912).

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

646986975408 is a wasteful number, since it uses less digits than its factorization.

646986975408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195346346 (or 195346337 counting only the distinct ones).

The product of its (nonzero) digits is 627056640, while the sum is 72.

The spelling of 646986975408 in words is "six hundred forty-six billion, nine hundred eighty-six million, nine hundred seventy-five thousand, four hundred eight".