115937721 has 6 divisors (see below), whose sum is σ = 167465610. Its totient is φ = 77291808.

The previous prime is 115937713. The next prime is 115937729. The reversal of 115937721 is 127739511.

It is an interprime number because it is at equal distance from previous prime (115937713) and next prime (115937729).

It can be written as a sum of positive squares in only one way, i.e., 76737600 + 39200121 = 8760^2 + 6261^2 .

It is not a de Polignac number, because 115937721 - 2³ = 115937713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (115937729) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6440976 + ... + 6440993.

It is an arithmetic number, because the mean of its divisors is an integer number (27910935).

Almost surely, 2^115937721 is an apocalyptic number.

It is an amenable number.

115937721 is a deficient number, since it is larger than the sum of its proper divisors (51527889).

115937721 is a wasteful number, since it uses less digits than its factorization.

115937721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12881975 (or 12881972 counting only the distinct ones).

The product of its digits is 13230, while the sum is 36.

The square root of 115937721 is about 10767.4379961066. The cubic root of 115937721 is about 487.6126004201.

The spelling of 115937721 in words is "one hundred fifteen million, nine hundred thirty-seven thousand, seven hundred twenty-one".