63642561 has 4 divisors (see below), whose sum is σ = 84856752. Its totient is φ = 42428372.

The previous prime is 63642529. The next prime is 63642569. The reversal of 63642561 is 16524636.

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 not a de Polignac number, because 63642561 - 2⁵ = 63642529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63642569) 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, 10607091 + ... + 10607096.

It is an arithmetic number, because the mean of its divisors is an integer number (21214188).

Almost surely, 2^63642561 is an apocalyptic number.

It is an amenable number.

63642561 is a deficient number, since it is larger than the sum of its proper divisors (21214191).

63642561 is a wasteful number, since it uses less digits than its factorization.

63642561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21214190.

The product of its digits is 25920, while the sum is 33.

The square root of 63642561 is about 7977.6287830407. The cubic root of 63642561 is about 399.2539447858.

The spelling of 63642561 in words is "sixty-three million, six hundred forty-two thousand, five hundred sixty-one".