115979921 has 2 divisors, whose sum is σ = 115979922. Its totient is φ = 115979920.

The previous prime is 115979891. The next prime is 115979947. The reversal of 115979921 is 129979511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114725521 + 1254400 = 10711^2 + 1120^2 .

It is a cyclic number.

It is not a de Polignac number, because 115979921 - 2¹⁰ = 115978897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (115979951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57989960 + 57989961.

It is an arithmetic number, because the mean of its divisors is an integer number (57989961).

Almost surely, 2^115979921 is an apocalyptic number.

It is an amenable number.

115979921 is a deficient number, since it is larger than the sum of its proper divisors (1).

115979921 is an equidigital number, since it uses as much as digits as its factorization.

115979921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51030, while the sum is 44.

The square root of 115979921 is about 10769.3974297544. The cubic root of 115979921 is about 487.6717550404.

The spelling of 115979921 in words is "one hundred fifteen million, nine hundred seventy-nine thousand, nine hundred twenty-one".