15187851121 has 3 divisors (see below), whose sum is σ = 15187974361. Its totient is φ = 15187727882.

The previous prime is 15187851109. The next prime is 15187851179. The reversal of 15187851121 is 12115878151.

It is a happy number.

The square root of 15187851121 is 123239.

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

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, and also an emirpimes, since its reverse is a distinct semiprime: 12115878151 = 13 ⋅931990627.

It is a de Polignac number, because none of the positive numbers 2^k-15187851121 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15187851821) 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, 61620 + ... + 184858.

Almost surely, 2^15187851121 is an apocalyptic number.

15187851121 is the 123239-th square number.

15187851121 is the 61620-th centered octagonal number.

It is an amenable number.

15187851121 is a deficient number, since it is larger than the sum of its proper divisors (123240).

15187851121 is an frugal number, since it uses more digits than its factorization.

15187851121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246478 (or 123239 counting only the distinct ones).

The product of its digits is 22400, while the sum is 40.

The spelling of 15187851121 in words is "fifteen billion, one hundred eighty-seven million, eight hundred fifty-one thousand, one hundred twenty-one".