115402640561 has 4 divisors (see below), whose sum is σ = 124279766772. Its totient is φ = 106525514352.

The previous prime is 115402640539. The next prime is 115402640569. The reversal of 115402640561 is 165046204511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165046204511 = 97 ⋅1701507263.

It can be written as a sum of positive squares in 2 ways, for example, as 13166415025 + 102236225536 = 114745^2 + 319744^2 .

It is a cyclic number.

It is not a de Polignac number, because 115402640561 - 2³⁰ = 114328898737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115402640569) 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, 4438563086 + ... + 4438563111.

It is an arithmetic number, because the mean of its divisors is an integer number (31069941693).

Almost surely, 2^115402640561 is an apocalyptic number.

It is an amenable number.

115402640561 is a deficient number, since it is larger than the sum of its proper divisors (8877126211).

115402640561 is an equidigital number, since it uses as much as digits as its factorization.

115402640561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8877126210.

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 115402640561 in words is "one hundred fifteen billion, four hundred two million, six hundred forty thousand, five hundred sixty-one".