15318981118809 has 21 divisors (see below), whose sum is σ = 22968123275919. Its totient is φ = 10212583628160.

The previous prime is 15318981118807. The next prime is 15318981118823. The reversal of 15318981118809 is 90881118981351.

The square root of 15318981118809 is 3913947.

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

15318981118809 is a `hidden beast` number, since 1 + 531 + 8 + 9 + 8 + 1 + 1 + 18 + 80 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8583710461209 + 6735270657600 = 2929797^2 + 2595240^2 .

It is not a de Polignac number, because 15318981118809 - 2¹ = 15318981118807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15318981118801) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 105604089 + ... + 105749049.

Almost surely, 2^{15318981118809} is an apocalyptic number.

15318981118809 is the 3913947-th square number.

15318981118809 is the 1956974-th centered octagonal number.

It is an amenable number.

15318981118809 is a deficient number, since it is larger than the sum of its proper divisors (7649142157110).

15318981118809 is an frugal number, since it uses more digits than its factorization.

15318981118809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289940 (or 144964 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 63.

The spelling of 15318981118809 in words is "fifteen trillion, three hundred eighteen billion, nine hundred eighty-one million, one hundred eighteen thousand, eight hundred nine".