115531021 has 2 divisors, whose sum is σ = 115531022. Its totient is φ = 115531020.

The previous prime is 115530973. The next prime is 115531049. The reversal of 115531021 is 120135511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59505796 + 56025225 = 7714^2 + 7485^2 .

It is an emirp because it is prime and its reverse (120135511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 115531021 - 2⁹ = 115530509 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 115531021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (115531051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57765510 + 57765511.

It is an arithmetic number, because the mean of its divisors is an integer number (57765511).

Almost surely, 2^115531021 is an apocalyptic number.

It is an amenable number.

115531021 is a deficient number, since it is larger than the sum of its proper divisors (1).

115531021 is an equidigital number, since it uses as much as digits as its factorization.

115531021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 115531021 is about 10748.5357607443. The cubic root of 115531021 is about 487.0417641029.

Adding to 115531021 its reverse (120135511), we get a palindrome (235666532).

The spelling of 115531021 in words is "one hundred fifteen million, five hundred thirty-one thousand, twenty-one".