18638040 has 32 divisors (see below), whose sum is σ = 55914480. Its totient is φ = 4970112.

The previous prime is 18638029. The next prime is 18638063. The reversal of 18638040 is 4083681.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 18637989 and 18638007.

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 7 ways as a sum of consecutive naturals, for example, 77539 + ... + 77778.

Almost surely, 2^18638040 is an apocalyptic number.

18638040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18638040 is an abundant number, since it is smaller than the sum of its proper divisors (37276440).

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

18638040 is a wasteful number, since it uses less digits than its factorization.

18638040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155331 (or 155327 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 18638040 is about 4317.1796349005. The cubic root of 18638040 is about 265.1348074047.

It can be divided in two parts, 186 and 38040, that added together give a triangular number (38226 = T₂₇₆).

The spelling of 18638040 in words is "eighteen million, six hundred thirty-eight thousand, forty".