18940872 has 64 divisors (see below), whose sum is σ = 50616000. Its totient is φ = 5889024.

The previous prime is 18940871. The next prime is 18940877. The reversal of 18940872 is 27804981.

It is a self number, because there is not a number n which added to its sum of digits gives 18940872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18940871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33004 + ... + 33572.

It is an arithmetic number, because the mean of its divisors is an integer number (790875).

Almost surely, 2^18940872 is an apocalyptic number.

18940872 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 18940872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25308000).

18940872 is an abundant number, since it is smaller than the sum of its proper divisors (31675128).

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

18940872 is a wasteful number, since it uses less digits than its factorization.

18940872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670 (or 666 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 18940872 is about 4352.1112118143. Note that the first 3 decimals coincide. The cubic root of 18940872 is about 266.5630750409.

The spelling of 18940872 in words is "eighteen million, nine hundred forty thousand, eight hundred seventy-two".