115107821 has 4 divisors (see below), whose sum is σ = 115130652. Its totient is φ = 115084992.

The previous prime is 115107779. The next prime is 115107857. The reversal of 115107821 is 128701511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43705321 + 71402500 = 6611^2 + 8450^2 .

It is a cyclic number.

It is not a de Polignac number, because 115107821 - 2²⁶ = 47998957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115107121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140 + ... + 15173.

It is an arithmetic number, because the mean of its divisors is an integer number (28782663).

Almost surely, 2^115107821 is an apocalyptic number.

It is an amenable number.

115107821 is a deficient number, since it is larger than the sum of its proper divisors (22831).

115107821 is an equidigital number, since it uses as much as digits as its factorization.

115107821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22830.

The product of its (nonzero) digits is 560, while the sum is 26.

The square root of 115107821 is about 10728.8312970239. The cubic root of 115107821 is about 486.4463446222.

The spelling of 115107821 in words is "one hundred fifteen million, one hundred seven thousand, eight hundred twenty-one".