18390939 has 8 divisors (see below), whose sum is σ = 28024320. Its totient is φ = 10509096.

The previous prime is 18390937. The next prime is 18390943. The reversal of 18390939 is 93909381.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18390939 - 2¹ = 18390937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18390939.

It is not an unprimeable number, because it can be changed into a prime (18390937) 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, 437859 + ... + 437900.

It is an arithmetic number, because the mean of its divisors is an integer number (3503040).

Almost surely, 2^18390939 is an apocalyptic number.

18390939 is a deficient number, since it is larger than the sum of its proper divisors (9633381).

18390939 is an equidigital number, since it uses as much as digits as its factorization.

18390939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875769.

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 18390939 is about 4288.4658095874. The cubic root of 18390939 is about 263.9578818254.

The spelling of 18390939 in words is "eighteen million, three hundred ninety thousand, nine hundred thirty-nine".