18521157 has 8 divisors (see below), whose sum is σ = 24804576. Its totient is φ = 12292592.

The previous prime is 18521137. The next prime is 18521159. The reversal of 18521157 is 75112581.

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

It is a cyclic number.

It is not a de Polignac number, because 18521157 - 2⁶ = 18521093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18521159) by changing a digit.

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, 12918 + ... + 14279.

It is an arithmetic number, because the mean of its divisors is an integer number (3100572).

Almost surely, 2^18521157 is an apocalyptic number.

It is an amenable number.

18521157 is a deficient number, since it is larger than the sum of its proper divisors (6283419).

18521157 is a wasteful number, since it uses less digits than its factorization.

18521157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27427.

The product of its digits is 2800, while the sum is 30.

The square root of 18521157 is about 4303.6213820456. The cubic root of 18521157 is about 264.5794063828.

The spelling of 18521157 in words is "eighteen million, five hundred twenty-one thousand, one hundred fifty-seven".