18390940 has 24 divisors (see below), whose sum is σ = 40893552. Its totient is φ = 6923520.

The previous prime is 18390937. The next prime is 18390943. The reversal of 18390940 is 4909381.

It is an interprime number because it is at equal distance from previous prime (18390937) and next prime (18390943).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 18390896 and 18390905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18390943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26706 + ... + 27385.

It is an arithmetic number, because the mean of its divisors is an integer number (1703898).

Almost surely, 2^18390940 is an apocalyptic number.

18390940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18390940 is an abundant number, since it is smaller than the sum of its proper divisors (22502612).

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

18390940 is a wasteful number, since it uses less digits than its factorization.

18390940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54117 (or 54115 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 18390940 is about 4288.4659261792. The cubic root of 18390940 is about 263.9578866096.

The spelling of 18390940 in words is "eighteen million, three hundred ninety thousand, nine hundred forty".