646138650 has 24 divisors (see below), whose sum is σ = 1602424224. Its totient is φ = 172303600.

The previous prime is 646138579. The next prime is 646138667. The reversal of 646138650 is 56831646.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 646138599 and 646138608.

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 11 ways as a sum of consecutive naturals, for example, 2153646 + ... + 2153945.

It is an arithmetic number, because the mean of its divisors is an integer number (66767676).

Almost surely, 2^646138650 is an apocalyptic number.

646138650 is an abundant number, since it is smaller than the sum of its proper divisors (956285574).

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

646138650 is a wasteful number, since it uses less digits than its factorization.

646138650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4307606 (or 4307601 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 646138650 is about 25419.2574635846. The cubic root of 646138650 is about 864.5203885596.

The spelling of 646138650 in words is "six hundred forty-six million, one hundred thirty-eight thousand, six hundred fifty".