18572121 has 12 divisors (see below), whose sum is σ = 27266980. Its totient is φ = 12178080.

The previous prime is 18572111. The next prime is 18572153. The reversal of 18572121 is 12127581.

It can be written as a sum of positive squares in 2 ways, for example, as 5934096 + 12638025 = 2436^2 + 3555^2 .

It is not a de Polignac number, because 18572121 - 2⁵ = 18572089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18572111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16366 + ... + 17463.

Almost surely, 2^18572121 is an apocalyptic number.

It is an amenable number.

18572121 is a deficient number, since it is larger than the sum of its proper divisors (8694859).

18572121 is a wasteful number, since it uses less digits than its factorization.

18572121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33896 (or 33893 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 18572121 is about 4309.5383743506. The cubic root of 18572121 is about 264.8218620045.

The spelling of 18572121 in words is "eighteen million, five hundred seventy-two thousand, one hundred twenty-one".