64721393 has 8 divisors (see below), whose sum is σ = 70682976. Its totient is φ = 58772800.

The previous prime is 64721383. The next prime is 64721441. The reversal of 64721393 is 39312746.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64721393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64721323) 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, 9305 + ... + 14697.

It is an arithmetic number, because the mean of its divisors is an integer number (8835372).

Almost surely, 2^64721393 is an apocalyptic number.

It is an amenable number.

64721393 is a deficient number, since it is larger than the sum of its proper divisors (5961583).

64721393 is a wasteful number, since it uses less digits than its factorization.

64721393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6495.

The product of its digits is 27216, while the sum is 35.

The square root of 64721393 is about 8044.9607208488. The cubic root of 64721393 is about 401.4972903938.

The spelling of 64721393 in words is "sixty-four million, seven hundred twenty-one thousand, three hundred ninety-three".