6639790321 has 4 divisors (see below), whose sum is σ = 6752329200. Its totient is φ = 6527251444.

The previous prime is 6639790319. The next prime is 6639790349. The reversal of 6639790321 is 1230979366.

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 6639790321 - 2¹ = 6639790319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639790361) 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, 56269351 + ... + 56269468.

It is an arithmetic number, because the mean of its divisors is an integer number (1688082300).

Almost surely, 2^6639790321 is an apocalyptic number.

It is an amenable number.

6639790321 is a deficient number, since it is larger than the sum of its proper divisors (112538879).

6639790321 is a wasteful number, since it uses less digits than its factorization.

6639790321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112538878.

The product of its (nonzero) digits is 367416, while the sum is 46.

The square root of 6639790321 is about 81484.9085475341. The cubic root of 6639790321 is about 1879.5394904395.

The spelling of 6639790321 in words is "six billion, six hundred thirty-nine million, seven hundred ninety thousand, three hundred twenty-one".