64515521 has 8 divisors (see below), whose sum is σ = 73794240. Its totient is φ = 55252368.

The previous prime is 64515487. The next prime is 64515533. The reversal of 64515521 is 12551546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64515521 - 2¹⁰ = 64514497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64515551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7055 + ... + 13371.

It is an arithmetic number, because the mean of its divisors is an integer number (9224280).

Almost surely, 2^64515521 is an apocalyptic number.

It is an amenable number.

64515521 is a deficient number, since it is larger than the sum of its proper divisors (9278719).

64515521 is a wasteful number, since it uses less digits than its factorization.

64515521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7783.

The product of its digits is 6000, while the sum is 29.

The square root of 64515521 is about 8032.1554392330. The cubic root of 64515521 is about 401.0711312178.

The spelling of 64515521 in words is "sixty-four million, five hundred fifteen thousand, five hundred twenty-one".