64339921 has 4 divisors (see below), whose sum is σ = 64616292. Its totient is φ = 64063552.

The previous prime is 64339879. The next prime is 64339927. The reversal of 64339921 is 12993346.

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 4060225 + 60279696 = 2015^2 + 7764^2 .

It is a cyclic number.

It is not a de Polignac number, because 64339921 - 2¹¹ = 64337873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64339927) 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, 137836 + ... + 138301.

It is an arithmetic number, because the mean of its divisors is an integer number (16154073).

Almost surely, 2^64339921 is an apocalyptic number.

It is an amenable number.

64339921 is a deficient number, since it is larger than the sum of its proper divisors (276371).

64339921 is a wasteful number, since it uses less digits than its factorization.

64339921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276370.

The product of its digits is 34992, while the sum is 37.

The square root of 64339921 is about 8021.2169276239. The cubic root of 64339921 is about 400.7069186790.

The spelling of 64339921 in words is "sixty-four million, three hundred thirty-nine thousand, nine hundred twenty-one".