664504732346421 has 4 divisors (see below), whose sum is σ = 886006309795232. Its totient is φ = 443003154897612.

The previous prime is 664504732346417. The next prime is 664504732346449. The reversal of 664504732346421 is 124643237405466.

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 not a de Polignac number, because 664504732346421 - 2² = 664504732346417 is a prime.

It is a super-2 number, since 2×664504732346421² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664504732386421) 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, 110750788724401 + ... + 110750788724406.

It is an arithmetic number, because the mean of its divisors is an integer number (221501577448808).

Almost surely, 2^{664504732346421} is an apocalyptic number.

It is an amenable number.

664504732346421 is a deficient number, since it is larger than the sum of its proper divisors (221501577448811).

664504732346421 is a wasteful number, since it uses less digits than its factorization.

664504732346421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221501577448810.

The product of its (nonzero) digits is 69672960, while the sum is 57.

The spelling of 664504732346421 in words is "six hundred sixty-four trillion, five hundred four billion, seven hundred thirty-two million, three hundred forty-six thousand, four hundred twenty-one".