115719821 has 6 divisors (see below), whose sum is σ = 134612910. Its totient is φ = 99188376.

The previous prime is 115719817. The next prime is 115719887. The reversal of 115719821 is 128917511.

It can be written as a sum of positive squares in only one way, i.e., 110544196 + 5175625 = 10514^2 + 2275^2 .

It is not a de Polignac number, because 115719821 - 2² = 115719817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115719521) 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 5 ways as a sum of consecutive naturals, for example, 1180766 + ... + 1180863.

It is an arithmetic number, because the mean of its divisors is an integer number (22435485).

Almost surely, 2^115719821 is an apocalyptic number.

It is an amenable number.

115719821 is a deficient number, since it is larger than the sum of its proper divisors (18893089).

115719821 is an equidigital number, since it uses as much as digits as its factorization.

115719821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2361643 (or 2361636 counting only the distinct ones).

The product of its digits is 5040, while the sum is 35.

The square root of 115719821 is about 10757.3147671712. The cubic root of 115719821 is about 487.3069264803.

The spelling of 115719821 in words is "one hundred fifteen million, seven hundred nineteen thousand, eight hundred twenty-one".