18686840 has 16 divisors (see below), whose sum is σ = 42045480. Its totient is φ = 7474720.

The previous prime is 18686827. The next prime is 18686849. The reversal of 18686840 is 4868681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18686849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233546 + ... + 233625.

Almost surely, 2^18686840 is an apocalyptic number.

18686840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18686840 is an abundant number, since it is smaller than the sum of its proper divisors (23358640).

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

18686840 is a wasteful number, since it uses less digits than its factorization.

18686840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467182 (or 467178 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 41.

The square root of 18686840 is about 4322.8277782026. The cubic root of 18686840 is about 265.3660066552.

The spelling of 18686840 in words is "eighteen million, six hundred eighty-six thousand, eight hundred forty".