64563521 has 4 divisors (see below), whose sum is σ = 70432944. Its totient is φ = 58694100.

The previous prime is 64563517. The next prime is 64563529. The reversal of 64563521 is 12536546.

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 64563521 - 2² = 64563517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64563529) 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, 2934695 + ... + 2934716.

It is an arithmetic number, because the mean of its divisors is an integer number (17608236).

Almost surely, 2^64563521 is an apocalyptic number.

It is an amenable number.

64563521 is a deficient number, since it is larger than the sum of its proper divisors (5869423).

64563521 is a wasteful number, since it uses less digits than its factorization.

64563521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5869422.

The product of its digits is 21600, while the sum is 32.

The square root of 64563521 is about 8035.1428736520. The cubic root of 64563521 is about 401.1705731381.

The spelling of 64563521 in words is "sixty-four million, five hundred sixty-three thousand, five hundred twenty-one".