64565521 has 4 divisors (see below), whose sum is σ = 64584000. Its totient is φ = 64547044.

The previous prime is 64565509. The next prime is 64565537. The reversal of 64565521 is 12556546.

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 64565521 - 2⁹ = 64565009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64565551) 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, 2221 + ... + 11578.

It is an arithmetic number, because the mean of its divisors is an integer number (16146000).

Almost surely, 2^64565521 is an apocalyptic number.

It is an amenable number.

64565521 is a deficient number, since it is larger than the sum of its proper divisors (18479).

64565521 is a wasteful number, since it uses less digits than its factorization.

64565521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18478.

The product of its digits is 36000, while the sum is 34.

The square root of 64565521 is about 8035.2673259824. The cubic root of 64565521 is about 401.1747154816.

It can be divided in two parts, 645 and 65521, that added together give a palindrome (66166).

The spelling of 64565521 in words is "sixty-four million, five hundred sixty-five thousand, five hundred twenty-one".