115678721 has 2 divisors, whose sum is σ = 115678722. Its totient is φ = 115678720.

The previous prime is 115678637. The next prime is 115678723. The reversal of 115678721 is 127876511.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91776400 + 23902321 = 9580^2 + 4889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115678721 is a prime.

Together with 115678723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (115678723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57839360 + 57839361.

It is an arithmetic number, because the mean of its divisors is an integer number (57839361).

Almost surely, 2^115678721 is an apocalyptic number.

It is an amenable number.

115678721 is a deficient number, since it is larger than the sum of its proper divisors (1).

115678721 is an equidigital number, since it uses as much as digits as its factorization.

115678721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 38.

The square root of 115678721 is about 10755.4042694824. The cubic root of 115678721 is about 487.2492276750.

The spelling of 115678721 in words is "one hundred fifteen million, six hundred seventy-eight thousand, seven hundred twenty-one".