18981572 has 12 divisors (see below), whose sum is σ = 33326076. Its totient is φ = 9459840.

The previous prime is 18981563. The next prime is 18981577. The reversal of 18981572 is 27518981.

It can be written as a sum of positive squares in 2 ways, for example, as 3740356 + 15241216 = 1934^2 + 3904^2 .

It is not an unprimeable number, because it can be changed into a prime (18981577) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6329 + ... + 8832.

It is an arithmetic number, because the mean of its divisors is an integer number (2777173).

Almost surely, 2^18981572 is an apocalyptic number.

It is an amenable number.

18981572 is a deficient number, since it is larger than the sum of its proper divisors (14344504).

18981572 is a wasteful number, since it uses less digits than its factorization.

18981572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15478 (or 15476 counting only the distinct ones).

The product of its digits is 40320, while the sum is 41.

The square root of 18981572 is about 4356.7845941703. The cubic root of 18981572 is about 266.7538680094.

The spelling of 18981572 in words is "eighteen million, nine hundred eighty-one thousand, five hundred seventy-two".