63723521 has 4 divisors (see below), whose sum is σ = 64057344. Its totient is φ = 63389700.

The previous prime is 63723487. The next prime is 63723523. The reversal of 63723521 is 12532736.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63723521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63723523) 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, 166625 + ... + 167006.

It is an arithmetic number, because the mean of its divisors is an integer number (16014336).

Almost surely, 2^63723521 is an apocalyptic number.

It is an amenable number.

63723521 is a deficient number, since it is larger than the sum of its proper divisors (333823).

63723521 is a wasteful number, since it uses less digits than its factorization.

63723521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333822.

The product of its digits is 7560, while the sum is 29.

The square root of 63723521 is about 7982.7013598155. The cubic root of 63723521 is about 399.4231706529.

The spelling of 63723521 in words is "sixty-three million, seven hundred twenty-three thousand, five hundred twenty-one".