18221267604 has 24 divisors (see below), whose sum is σ = 43665381088. Its totient is φ = 5909600160.

The previous prime is 18221267599. The next prime is 18221267611. The reversal of 18221267604 is 40676212281.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20519002 + ... + 20519889.

Almost surely, 2^18221267604 is an apocalyptic number.

It is an amenable number.

18221267604 is an abundant number, since it is smaller than the sum of its proper divisors (25444113484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18221267604 is a wasteful number, since it uses less digits than its factorization.

18221267604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41038935 (or 41038933 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

Adding to 18221267604 its reverse (40676212281), we get a palindrome (58897479885).

The spelling of 18221267604 in words is "eighteen billion, two hundred twenty-one million, two hundred sixty-seven thousand, six hundred four".