18990972 has 288 divisors, whose sum is σ = 70447104. Its totient is φ = 4147200.

The previous prime is 18990943. The next prime is 18990973. The reversal of 18990972 is 27909981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990973) 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 95 ways as a sum of consecutive naturals, for example, 612597 + ... + 612627.

It is an arithmetic number, because the mean of its divisors is an integer number (244608).

Almost surely, 2^18990972 is an apocalyptic number.

18990972 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 18990972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35223552).

18990972 is an abundant number, since it is smaller than the sum of its proper divisors (51456132).

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

18990972 is a wasteful number, since it uses less digits than its factorization.

18990972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 18990972 is about 4357.8632378724. The cubic root of 18990972 is about 266.7978944395.

It can be divided in two parts, 189909 and 72, that added together give a palindrome (189981).

The spelling of 18990972 in words is "eighteen million, nine hundred ninety thousand, nine hundred seventy-two".