2179317921 has 16 divisors (see below), whose sum is σ = 3174847488. Its totient is φ = 1318744400.

The previous prime is 2179317859. The next prime is 2179317923. The reversal of 2179317921 is 1297139712.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2179317921 - 2⁶ = 2179317857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2179317923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29685 + ... + 72386.

It is an arithmetic number, because the mean of its divisors is an integer number (198427968).

Almost surely, 2^2179317921 is an apocalyptic number.

It is an amenable number.

2179317921 is a deficient number, since it is larger than the sum of its proper divisors (995529567).

2179317921 is a wasteful number, since it uses less digits than its factorization.

2179317921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102732.

The product of its digits is 47628, while the sum is 42.

The square root of 2179317921 is about 46683.1652847148. The cubic root of 2179317921 is about 1296.5030120231.

The spelling of 2179317921 in words is "two billion, one hundred seventy-nine million, three hundred seventeen thousand, nine hundred twenty-one".