63521720 has 16 divisors (see below), whose sum is σ = 142923960. Its totient is φ = 25408672.

The previous prime is 63521683. The next prime is 63521723. The reversal of 63521720 is 2712536.

63521720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 63521720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63521723) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 793982 + ... + 794061.

Almost surely, 2^63521720 is an apocalyptic number.

It is an amenable number.

63521720 is an abundant number, since it is smaller than the sum of its proper divisors (79402240).

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

63521720 is a wasteful number, since it uses less digits than its factorization.

63521720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1588054 (or 1588050 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 63521720 is about 7970.0514427449. The cubic root of 63521720 is about 399.0010908612.

The spelling of 63521720 in words is "sixty-three million, five hundred twenty-one thousand, seven hundred twenty".