18221369372 has 6 divisors (see below), whose sum is σ = 31887396408. Its totient is φ = 9110684684.

The previous prime is 18221369359. The next prime is 18221369389. The reversal of 18221369372 is 27396312281.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2277671168 + ... + 2277671175.

It is an arithmetic number, because the mean of its divisors is an integer number (5314566068).

Almost surely, 2^18221369372 is an apocalyptic number.

It is an amenable number.

18221369372 is a deficient number, since it is larger than the sum of its proper divisors (13666027036).

18221369372 is a wasteful number, since it uses less digits than its factorization.

18221369372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4555342347 (or 4555342345 counting only the distinct ones).

The product of its digits is 217728, while the sum is 44.

The spelling of 18221369372 in words is "eighteen billion, two hundred twenty-one million, three hundred sixty-nine thousand, three hundred seventy-two".