646643524 has 12 divisors (see below), whose sum is σ = 1162210924. Its totient is φ = 314583264.

The previous prime is 646643489. The next prime is 646643527. The reversal of 646643524 is 425346646.

It can be written as a sum of positive squares in 2 ways, for example, as 558471424 + 88172100 = 23632^2 + 9390^2 .

It is a super-2 number, since 2×646643524² = 836295694262277152, which contains 22 as substring.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (646643527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2184459 + ... + 2184754.

Almost surely, 2^646643524 is an apocalyptic number.

It is an amenable number.

646643524 is a deficient number, since it is larger than the sum of its proper divisors (515567400).

646643524 is a wasteful number, since it uses less digits than its factorization.

646643524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4369254 (or 4369252 counting only the distinct ones).

The product of its digits is 414720, while the sum is 40.

The square root of 646643524 is about 25429.1864596569. The cubic root of 646643524 is about 864.7455003233.

The spelling of 646643524 in words is "six hundred forty-six million, six hundred forty-three thousand, five hundred twenty-four".