18158940 has 72 divisors (see below), whose sum is σ = 55823040. Its totient is φ = 4777344.

The previous prime is 18158929. The next prime is 18158951. The reversal of 18158940 is 4985181.

It is an interprime number because it is at equal distance from previous prime (18158929) and next prime (18158951).

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

It is a junction number, because it is equal to n+sod(n) for n = 18158895 and 18158904.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13582 + ... + 14858.

It is an arithmetic number, because the mean of its divisors is an integer number (775320).

Almost surely, 2^18158940 is an apocalyptic number.

18158940 is a gapful number since it is divisible by the number (10) 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 18158940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27911520).

18158940 is an abundant number, since it is smaller than the sum of its proper divisors (37664100).

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

18158940 is a wasteful number, since it uses less digits than its factorization.

18158940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1371 (or 1366 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 18158940 is about 4261.3307780551. The cubic root of 18158940 is about 262.8432516401.

The spelling of 18158940 in words is "eighteen million, one hundred fifty-eight thousand, nine hundred forty".