15918559897249 has 3 divisors (see below), whose sum is σ = 15918563887057. Its totient is φ = 15918555907442.

The previous prime is 15918559897243. The next prime is 15918559897307. The reversal of 15918559897249 is 94279895581951.

The square root of 15918559897249 is 3989807.

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

15918559897249 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 15918559897249 - 2²³ = 15918551508641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15918559897243) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1994904 + ... + 5984710.

Almost surely, 2^{15918559897249} is an apocalyptic number.

15918559897249 is the 3989807-th square number.

15918559897249 is the 1994904-th centered octagonal number.

It is an amenable number.

15918559897249 is a deficient number, since it is larger than the sum of its proper divisors (3989808).

15918559897249 is an frugal number, since it uses more digits than its factorization.

15918559897249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7979614 (or 3989807 counting only the distinct ones).

The product of its digits is 2939328000, while the sum is 82.

The spelling of 15918559897249 in words is "fifteen trillion, nine hundred eighteen billion, five hundred fifty-nine million, eight hundred ninety-seven thousand, two hundred forty-nine".