18990157 has 16 divisors (see below), whose sum is σ = 20839680. Its totient is φ = 17248000.

The previous prime is 18990143. The next prime is 18990163. The reversal of 18990157 is 75109981.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18990157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990187) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47157 + ... + 47557.

It is an arithmetic number, because the mean of its divisors is an integer number (1302480).

Almost surely, 2^18990157 is an apocalyptic number.

It is an amenable number.

18990157 is a deficient number, since it is larger than the sum of its proper divisors (1849523).

18990157 is a wasteful number, since it uses less digits than its factorization.

18990157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 18990157 is about 4357.7697277392. The cubic root of 18990157 is about 266.7940778296.

The spelling of 18990157 in words is "eighteen million, nine hundred ninety thousand, one hundred fifty-seven".