115661405 has 4 divisors (see below), whose sum is σ = 138793692. Its totient is φ = 92529120.

The previous prime is 115661401. The next prime is 115661431. The reversal of 115661405 is 504166511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 68079001 + 47582404 = 8251^2 + 6898^2 .

It is not a de Polignac number, because 115661405 - 2² = 115661401 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 (115661401) 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, 11566136 + ... + 11566145.

It is an arithmetic number, because the mean of its divisors is an integer number (34698423).

Almost surely, 2^115661405 is an apocalyptic number.

It is an amenable number.

115661405 is a deficient number, since it is larger than the sum of its proper divisors (23132287).

115661405 is an equidigital number, since it uses as much as digits as its factorization.

115661405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23132286.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 115661405 is about 10754.5992486936. The cubic root of 115661405 is about 487.2249142761.

The spelling of 115661405 in words is "one hundred fifteen million, six hundred sixty-one thousand, four hundred five".