21183721007 has 8 divisors (see below), whose sum is σ = 21674607696. Its totient is φ = 20698258752.

The previous prime is 21183721001. The next prime is 21183721019. The reversal of 21183721007 is 70012738112.

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

It is a cyclic number.

It is not a de Polignac number, because 21183721007 - 2⁴ = 21183720991 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 (21183721001) 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, 1348208 + ... + 1363829.

It is an arithmetic number, because the mean of its divisors is an integer number (2709325962).

Almost surely, 2^21183721007 is an apocalyptic number.

21183721007 is a deficient number, since it is larger than the sum of its proper divisors (490886689).

21183721007 is a wasteful number, since it uses less digits than its factorization.

21183721007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712217.

The product of its (nonzero) digits is 4704, while the sum is 32.

The spelling of 21183721007 in words is "twenty-one billion, one hundred eighty-three million, seven hundred twenty-one thousand, seven".