64729621 has 4 divisors (see below), whose sum is σ = 70614144. Its totient is φ = 58845100.

The previous prime is 64729607. The next prime is 64729627. The reversal of 64729621 is 12692746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64729621 - 2⁹ = 64729109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64729627) 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, 2942245 + ... + 2942266.

It is an arithmetic number, because the mean of its divisors is an integer number (17653536).

Almost surely, 2^64729621 is an apocalyptic number.

It is an amenable number.

64729621 is a deficient number, since it is larger than the sum of its proper divisors (5884523).

64729621 is a wasteful number, since it uses less digits than its factorization.

64729621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5884522.

The product of its digits is 36288, while the sum is 37.

The square root of 64729621 is about 8045.4720806178. The cubic root of 64729621 is about 401.5143037262.

The spelling of 64729621 in words is "sixty-four million, seven hundred twenty-nine thousand, six hundred twenty-one".