646850920 has 32 divisors (see below), whose sum is σ = 1456266600. Its totient is φ = 258588928.

The previous prime is 646850917. The next prime is 646850933. The reversal of 646850920 is 29058646.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 644245924 + 2604996 = 25382^2 + 1614^2 .

It is a super-2 number, since 2×646850920² = 836832225409692800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

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 7 ways as a sum of consecutive naturals, for example, 85866 + ... + 93094.

Almost surely, 2^646850920 is an apocalyptic number.

It is an amenable number.

646850920 is an abundant number, since it is smaller than the sum of its proper divisors (809415680).

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

646850920 is a wasteful number, since it uses less digits than its factorization.

646850920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9477 (or 9473 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 646850920 is about 25433.2640453403. The cubic root of 646850920 is about 864.8379395014.

The spelling of 646850920 in words is "six hundred forty-six million, eight hundred fifty thousand, nine hundred twenty".