64185021 has 16 divisors (see below), whose sum is σ = 100094400. Its totient is φ = 40537584.

The previous prime is 64185007. The next prime is 64185029. The reversal of 64185021 is 12058146.

It is not a de Polignac number, because 64185021 - 2⁶ = 64184957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64185029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62046 + ... + 63071.

It is an arithmetic number, because the mean of its divisors is an integer number (6255900).

Almost surely, 2^64185021 is an apocalyptic number.

It is an amenable number.

64185021 is a deficient number, since it is larger than the sum of its proper divisors (35909379).

64185021 is a wasteful number, since it uses less digits than its factorization.

64185021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125145 (or 125139 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 64185021 is about 8011.5554669490. Note that the first 3 decimals coincide. The cubic root of 64185021 is about 400.3850895628.

The spelling of 64185021 in words is "sixty-four million, one hundred eighty-five thousand, twenty-one".