10115111561 has 4 divisors (see below), whose sum is σ = 10280933124. Its totient is φ = 9949290000.

The previous prime is 10115111549. The next prime is 10115111563. The reversal of 10115111561 is 16511151101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16511151101 = 739 ⋅22342559.

It can be written as a sum of positive squares in 2 ways, for example, as 1837751161 + 8277360400 = 42869^2 + 90980^2 .

It is a cyclic number.

It is not a de Polignac number, because 10115111561 - 2²⁶ = 10048002697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10115111563) 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, 82910690 + ... + 82910811.

It is an arithmetic number, because the mean of its divisors is an integer number (2570233281).

Almost surely, 2^10115111561 is an apocalyptic number.

It is an amenable number.

10115111561 is a deficient number, since it is larger than the sum of its proper divisors (165821563).

10115111561 is an equidigital number, since it uses as much as digits as its factorization.

10115111561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165821562.

The product of its (nonzero) digits is 150, while the sum is 23.

Adding to 10115111561 its reverse (16511151101), we get a palindrome (26626262662).

The spelling of 10115111561 in words is "ten billion, one hundred fifteen million, one hundred eleven thousand, five hundred sixty-one".