646521552 has 30 divisors (see below), whose sum is σ = 1809362802. Its totient is φ = 215507136.

The previous prime is 646521541. The next prime is 646521553. The reversal of 646521552 is 255125646.

646521552 is a `hidden beast` number, since 646 + 5 + 2 + 1 + 5 + 5 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 642926736 + 3594816 = 25356^2 + 1896^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646521553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2244723 + ... + 2245010.

Almost surely, 2^646521552 is an apocalyptic number.

It is an amenable number.

646521552 is an abundant number, since it is smaller than the sum of its proper divisors (1162841250).

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

646521552 is a wasteful number, since it uses less digits than its factorization.

646521552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489747 (or 4489738 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 646521552 is about 25426.7880787173. The cubic root of 646521552 is about 864.6911265369.

The spelling of 646521552 in words is "six hundred forty-six million, five hundred twenty-one thousand, five hundred fifty-two".