18431049121 has 9 divisors (see below), whose sum is σ = 18531650361. Its totient is φ = 18330993264.

The previous prime is 18431049113. The next prime is 18431049179. The reversal of 18431049121 is 12194013481.

The square root of 18431049121 is 135761.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 21986721 + 18409062400 = 4689^2 + 135680^2 .

It is not a de Polignac number, because 18431049121 - 2³ = 18431049113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18431049191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 47380395 + ... + 47380783.

Almost surely, 2^18431049121 is an apocalyptic number.

18431049121 is the 135761-st square number.

18431049121 is the 67881-st centered octagonal number.

It is an amenable number.

18431049121 is a deficient number, since it is larger than the sum of its proper divisors (100601240).

18431049121 is an frugal number, since it uses more digits than its factorization.

18431049121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1476 (or 738 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The spelling of 18431049121 in words is "eighteen billion, four hundred thirty-one million, forty-nine thousand, one hundred twenty-one".