115121221 has 2 divisors, whose sum is σ = 115121222. Its totient is φ = 115121220.

The previous prime is 115121207. The next prime is 115121261. The reversal of 115121221 is 122121511.

It is a m-pointer prime, because the next prime (115121261) can be obtained adding 115121221 to its product of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111830625 + 3290596 = 10575^2 + 1814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115121221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 115121195 and 115121204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (115121261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57560610 + 57560611.

It is an arithmetic number, because the mean of its divisors is an integer number (57560611).

Almost surely, 2^115121221 is an apocalyptic number.

It is an amenable number.

115121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

115121221 is an equidigital number, since it uses as much as digits as its factorization.

115121221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40, while the sum is 16.

The square root of 115121221 is about 10729.4557643899. The cubic root of 115121221 is about 486.4652200500.

Adding to 115121221 its reverse (122121511), we get a palindrome (237242732).

The spelling of 115121221 in words is "one hundred fifteen million, one hundred twenty-one thousand, two hundred twenty-one".