646990938 has 24 divisors (see below), whose sum is σ = 1529251776. Its totient is φ = 196057800.

The previous prime is 646990937. The next prime is 646990969. The reversal of 646990938 is 839099646.

It is a happy number.

646990938 is a `hidden beast` number, since 6 + 469 + 90 + 93 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (646990933) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1633618 + ... + 1634013.

It is an arithmetic number, because the mean of its divisors is an integer number (63718824).

Almost surely, 2^646990938 is an apocalyptic number.

646990938 is an abundant number, since it is smaller than the sum of its proper divisors (882260838).

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

646990938 is a wasteful number, since it uses less digits than its factorization.

646990938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3267650 (or 3267647 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 54.

The square root of 646990938 is about 25436.0165513392. The cubic root of 646990938 is about 864.9003362292.

The spelling of 646990938 in words is "six hundred forty-six million, nine hundred ninety thousand, nine hundred thirty-eight".