64978521 has 8 divisors (see below), whose sum is σ = 87017280. Its totient is φ = 43129392.

The previous prime is 64978517. The next prime is 64978553. The reversal of 64978521 is 12587946.

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

It is not a de Polignac number, because 64978521 - 2² = 64978517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64978421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46605 + ... + 47978.

It is an arithmetic number, because the mean of its divisors is an integer number (10877160).

Almost surely, 2^64978521 is an apocalyptic number.

It is an amenable number.

64978521 is a deficient number, since it is larger than the sum of its proper divisors (22038759).

64978521 is a wasteful number, since it uses less digits than its factorization.

64978521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94815.

The product of its digits is 120960, while the sum is 42.

The square root of 64978521 is about 8060.9255672038. The cubic root of 64978521 is about 402.0282832010.

The spelling of 64978521 in words is "sixty-four million, nine hundred seventy-eight thousand, five hundred twenty-one".