18981072 has 120 divisors (see below), whose sum is σ = 60585408. Its totient is φ = 5491200.

The previous prime is 18981047. The next prime is 18981077. The reversal of 18981072 is 27018981.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18981077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36172 + ... + 36692.

Almost surely, 2^18981072 is an apocalyptic number.

18981072 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 18981072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30292704).

18981072 is an abundant number, since it is smaller than the sum of its proper divisors (41604336).

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

18981072 is a wasteful number, since it uses less digits than its factorization.

18981072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 18981072 is about 4356.7272120251. The cubic root of 18981072 is about 266.7515257709.

The spelling of 18981072 in words is "eighteen million, nine hundred eighty-one thousand, seventy-two".