18371440 has 40 divisors (see below), whose sum is σ = 43064208. Its totient is φ = 7288320.

The previous prime is 18371429. The next prime is 18371447. The reversal of 18371440 is 4417381.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18371399 and 18371408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18371447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9604 + ... + 11356.

Almost surely, 2^18371440 is an apocalyptic number.

18371440 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 18371440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21532104).

18371440 is an abundant number, since it is smaller than the sum of its proper divisors (24692768).

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

18371440 is a wasteful number, since it uses less digits than its factorization.

18371440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1897 (or 1891 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 18371440 is about 4286.1917829234. The cubic root of 18371440 is about 263.8645616889.

The spelling of 18371440 in words is "eighteen million, three hundred seventy-one thousand, four hundred forty".