18972 has 36 divisors (see below), whose sum is σ = 52416. Its totient is φ = 5760.

The previous prime is 18959. The next prime is 18973. The reversal of 18972 is 27981.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18973) by changing a digit.

18972 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 597 + ... + 627.

It is an arithmetic number, because the mean of its divisors is an integer number (1456).

2¹⁸⁹⁷² is an apocalyptic number.

18972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26208).

18972 is an abundant number, since it is smaller than the sum of its proper divisors (33444).

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

18972 is a wasteful number, since it uses less digits than its factorization.

18972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58 (or 53 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 18972 is about 137.7388833990. The cubic root of 18972 is about 26.6709021050.

Subtracting 18972 from its reverse (27981), we obtain a palindrome (9009).

It can be divided in two parts, 18 and 972, that added together give a triangular number (990 = T₄₄).

The spelling of 18972 in words is "eighteen thousand, nine hundred seventy-two".