18421157 has 16 divisors (see below), whose sum is σ = 19673280. Its totient is φ = 17227392.

The previous prime is 18421129. The next prime is 18421201. The reversal of 18421157 is 75112481.

It is a cyclic number.

It is not a de Polignac number, because 18421157 - 2⁶ = 18421093 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 (18421057) 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 15 ways as a sum of consecutive naturals, for example, 134393 + ... + 134529.

It is an arithmetic number, because the mean of its divisors is an integer number (1229580).

Almost surely, 2^18421157 is an apocalyptic number.

It is an amenable number.

18421157 is a deficient number, since it is larger than the sum of its proper divisors (1252123).

18421157 is a wasteful number, since it uses less digits than its factorization.

18421157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292.

The product of its digits is 2240, while the sum is 29.

The square root of 18421157 is about 4291.9875349306. The cubic root of 18421157 is about 264.1023717229.

The spelling of 18421157 in words is "eighteen million, four hundred twenty-one thousand, one hundred fifty-seven".