18273972 has 24 divisors (see below), whose sum is σ = 44884000. Its totient is φ = 5770656.

The previous prime is 18273961. The next prime is 18273979. The reversal of 18273972 is 27937281.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18273972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18273979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39847 + ... + 40302.

Almost surely, 2^18273972 is an apocalyptic number.

18273972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18273972 is an abundant number, since it is smaller than the sum of its proper divisors (26610028).

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

18273972 is a wasteful number, since it uses less digits than its factorization.

18273972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80175 (or 80173 counting only the distinct ones).

The product of its digits is 42336, while the sum is 39.

The square root of 18273972 is about 4274.8066622948. The cubic root of 18273972 is about 263.3970975570.

The spelling of 18273972 in words is "eighteen million, two hundred seventy-three thousand, nine hundred seventy-two".