115821979 has 16 divisors (see below), whose sum is σ = 144363520. Its totient is φ = 90473760.

The previous prime is 115821869. The next prime is 115821991. The reversal of 115821979 is 979128511.

It is not a de Polignac number, because 115821979 - 2¹⁷ = 115690907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (115824979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 867 + ... + 15244.

It is an arithmetic number, because the mean of its divisors is an integer number (9022720).

Almost surely, 2^115821979 is an apocalyptic number.

115821979 is a deficient number, since it is larger than the sum of its proper divisors (28541541).

115821979 is a wasteful number, since it uses less digits than its factorization.

115821979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16210.

The product of its digits is 45360, while the sum is 43.

The square root of 115821979 is about 10762.0620236087. The cubic root of 115821979 is about 487.4502832490.

The spelling of 115821979 in words is "one hundred fifteen million, eight hundred twenty-one thousand, nine hundred seventy-nine".