115564437661 has 16 divisors (see below), whose sum is σ = 122541254640. Its totient is φ = 108790456320.

The previous prime is 115564437631. The next prime is 115564437673. The reversal of 115564437661 is 166734465511.

It can be written as a sum of positive squares in 8 ways, for example, as 554602500 + 115009835161 = 23550^2 + 339131^2 .

It is a cyclic number.

It is not a de Polignac number, because 115564437661 - 2¹³ = 115564429469 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 (115564437631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1940845 + ... + 1999501.

It is an arithmetic number, because the mean of its divisors is an integer number (7658828415).

Almost surely, 2^115564437661 is an apocalyptic number.

It is an amenable number.

115564437661 is a deficient number, since it is larger than the sum of its proper divisors (6976816979).

115564437661 is a wasteful number, since it uses less digits than its factorization.

115564437661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60384.

The product of its digits is 1814400, while the sum is 49.

The spelling of 115564437661 in words is "one hundred fifteen billion, five hundred sixty-four million, four hundred thirty-seven thousand, six hundred sixty-one".