15918879083409 has 9 divisors (see below), whose sum is σ = 22993953743163. Its totient is φ = 10612578075912.

The previous prime is 15918879083383. The next prime is 15918879083417. The reversal of 15918879083409 is 90438097881951.

It is a happy number.

The square root of 15918879083409 is 3989847.

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

15918879083409 is a `hidden beast` number, since 1 + 59 + 1 + 8 + 8 + 7 + 90 + 83 + 409 = 666.

It can be written as a sum of positive squares in only one way, i.e., 304210711809 + 15614668371600 = 551553^2 + 3951540^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 15918879083409 - 2¹³ = 15918879075217 is a prime.

It is a super-2 number, since 2×15918879083409² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15918879083479) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11304567 + ... + 12634515.

Almost surely, 2^{15918879083409} is an apocalyptic number.

15918879083409 is the 3989847-th square number.

15918879083409 is the 1994924-th centered octagonal number.

It is an amenable number.

15918879083409 is a deficient number, since it is larger than the sum of its proper divisors (7075074659754).

15918879083409 is an frugal number, since it uses more digits than its factorization.

15918879083409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2659904 (or 1329952 counting only the distinct ones).

The product of its (nonzero) digits is 156764160, while the sum is 72.

The spelling of 15918879083409 in words is "fifteen trillion, nine hundred eighteen billion, eight hundred seventy-nine million, eighty-three thousand, four hundred nine".