646393968 has 60 divisors (see below), whose sum is σ = 1973465208. Its totient is φ = 195876480.

The previous prime is 646393939. The next prime is 646393981. The reversal of 646393968 is 869393646.

It is a happy number.

646393968 is a `hidden beast` number, since 6 + 463 + 93 + 96 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 202455 + ... + 205622.

Almost surely, 2^646393968 is an apocalyptic number.

It is an amenable number.

646393968 is an abundant number, since it is smaller than the sum of its proper divisors (1327071240).

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

646393968 is a wasteful number, since it uses less digits than its factorization.

646393968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408102 (or 408093 counting only the distinct ones).

The product of its digits is 5038848, while the sum is 54.

The square root of 646393968 is about 25424.2791048242. The cubic root of 646393968 is about 864.6342436637.

The spelling of 646393968 in words is "six hundred forty-six million, three hundred ninety-three thousand, nine hundred sixty-eight".