64253521 has 4 divisors (see below), whose sum is σ = 64273972. Its totient is φ = 64233072.

The previous prime is 64253443. The next prime is 64253549. The reversal of 64253521 is 12535246.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29855296 + 34398225 = 5464^2 + 5865^2 .

It is a cyclic number.

It is not a de Polignac number, because 64253521 - 2¹⁹ = 63729233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64253521.

It is not an unprimeable number, because it can be changed into a prime (64253561) 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, 4410 + ... + 12163.

It is an arithmetic number, because the mean of its divisors is an integer number (16068493).

Almost surely, 2^64253521 is an apocalyptic number.

It is an amenable number.

64253521 is a deficient number, since it is larger than the sum of its proper divisors (20451).

64253521 is a wasteful number, since it uses less digits than its factorization.

64253521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20450.

The product of its digits is 7200, while the sum is 28.

The square root of 64253521 is about 8015.8294018773. The cubic root of 64253521 is about 400.5274728752.

Adding to 64253521 its reverse (12535246), we get a palindrome (76788767).

The spelling of 64253521 in words is "sixty-four million, two hundred fifty-three thousand, five hundred twenty-one".