115123721 has 2 divisors, whose sum is σ = 115123722. Its totient is φ = 115123720.

The previous prime is 115123667. The next prime is 115123747. The reversal of 115123721 is 127321511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74304400 + 40819321 = 8620^2 + 6389^2 .

It is a cyclic number.

It is not a de Polignac number, because 115123721 - 2¹⁸ = 114861577 is a prime.

It is a super-3 number, since 3×115123721³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (115123751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57561860 + 57561861.

It is an arithmetic number, because the mean of its divisors is an integer number (57561861).

Almost surely, 2^115123721 is an apocalyptic number.

It is an amenable number.

115123721 is a deficient number, since it is larger than the sum of its proper divisors (1).

115123721 is an equidigital number, since it uses as much as digits as its factorization.

115123721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 420, while the sum is 23.

The square root of 115123721 is about 10729.5722654727. The cubic root of 115123721 is about 486.4687414229.

The spelling of 115123721 in words is "one hundred fifteen million, one hundred twenty-three thousand, seven hundred twenty-one".