18990356 has 24 divisors (see below), whose sum is σ = 41434176. Its totient is φ = 7398720.

The previous prime is 18990353. The next prime is 18990359. The reversal of 18990356 is 65309981.

It is an interprime number because it is at equal distance from previous prime (18990353) and next prime (18990359).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990353) 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, 30521 + ... + 31136.

It is an arithmetic number, because the mean of its divisors is an integer number (1726424).

Almost surely, 2^18990356 is an apocalyptic number.

It is an amenable number.

18990356 is an abundant number, since it is smaller than the sum of its proper divisors (22443820).

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

18990356 is a wasteful number, since it uses less digits than its factorization.

18990356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61679 (or 61677 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 18990356 is about 4357.7925604599. The cubic root of 18990356 is about 266.7950097481.

The spelling of 18990356 in words is "eighteen million, nine hundred ninety thousand, three hundred fifty-six".