13661093815 has 4 divisors (see below), whose sum is σ = 16393312584. Its totient is φ = 10928875048.

The previous prime is 13661093813. The next prime is 13661093827. The reversal of 13661093815 is 51839016631.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51839016631 = 269 ⋅192710099.

It is a cyclic number.

It is not a de Polignac number, because 13661093815 - 2¹ = 13661093813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13661093813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1366109377 + ... + 1366109386.

It is an arithmetic number, because the mean of its divisors is an integer number (4098328146).

Almost surely, 2^13661093815 is an apocalyptic number.

13661093815 is a deficient number, since it is larger than the sum of its proper divisors (2732218769).

13661093815 is an equidigital number, since it uses as much as digits as its factorization.

13661093815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2732218768.

The product of its (nonzero) digits is 116640, while the sum is 43.

The spelling of 13661093815 in words is "thirteen billion, six hundred sixty-one million, ninety-three thousand, eight hundred fifteen".