18867640 has 64 divisors (see below), whose sum is σ = 46798560. Its totient is φ = 6789120.

The previous prime is 18867617. The next prime is 18867647. The reversal of 18867640 is 4676881.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 18867593 and 18867602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18867647) 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, 60124 + ... + 60436.

Almost surely, 2^18867640 is an apocalyptic number.

18867640 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 18867640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23399280).

18867640 is an abundant number, since it is smaller than the sum of its proper divisors (27930920).

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

18867640 is a wasteful number, since it uses less digits than its factorization.

18867640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 18867640 is about 4343.6896758401. The cubic root of 18867640 is about 266.2190894780.

The spelling of 18867640 in words is "eighteen million, eight hundred sixty-seven thousand, six hundred forty".