18121396 has 12 divisors (see below), whose sum is σ = 31751748. Its totient is φ = 9049472.

The previous prime is 18121393. The next prime is 18121399. The reversal of 18121396 is 69312181.

It is an interprime number because it is at equal distance from previous prime (18121393) and next prime (18121399).

It can be written as a sum of positive squares in 2 ways, for example, as 11464996 + 6656400 = 3386^2 + 2580^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18121393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1590 + ... + 6226.

It is an arithmetic number, because the mean of its divisors is an integer number (2645979).

Almost surely, 2^18121396 is an apocalyptic number.

It is an amenable number.

18121396 is a deficient number, since it is larger than the sum of its proper divisors (13630352).

18121396 is a wasteful number, since it uses less digits than its factorization.

18121396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5618 (or 5616 counting only the distinct ones).

The product of its digits is 2592, while the sum is 31.

The square root of 18121396 is about 4256.9233021045. The cubic root of 18121396 is about 262.6619819596.

The spelling of 18121396 in words is "eighteen million, one hundred twenty-one thousand, three hundred ninety-six".