18372858921 has 6 divisors (see below), whose sum is σ = 26538574010. Its totient is φ = 12248572608.

The previous prime is 18372858893. The next prime is 18372858937. The reversal of 18372858921 is 12985827381.

18372858921 is a `hidden beast` number, since 1 + 8 + 37 + 2 + 8 + 589 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13056261696 + 5316597225 = 114264^2 + 72915^2 .

It is not a de Polignac number, because 18372858921 - 2¹⁰ = 18372857897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18372858941) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1020714376 + ... + 1020714393.

Almost surely, 2^18372858921 is an apocalyptic number.

It is an amenable number.

18372858921 is a deficient number, since it is larger than the sum of its proper divisors (8165715089).

18372858921 is a wasteful number, since it uses less digits than its factorization.

18372858921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2041428775 (or 2041428772 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The spelling of 18372858921 in words is "eighteen billion, three hundred seventy-two million, eight hundred fifty-eight thousand, nine hundred twenty-one".