121995917 has 2 divisors, whose sum is σ = 121995918. Its totient is φ = 121995916.

The previous prime is 121995899. The next prime is 121995971. The reversal of 121995917 is 719599121.

Together with next prime (121995971) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106894921 + 15100996 = 10339^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 121995917 - 2⁸ = 121995661 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121995317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60997958 + 60997959.

It is an arithmetic number, because the mean of its divisors is an integer number (60997959).

Almost surely, 2^121995917 is an apocalyptic number.

It is an amenable number.

121995917 is a deficient number, since it is larger than the sum of its proper divisors (1).

121995917 is an equidigital number, since it uses as much as digits as its factorization.

121995917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51030, while the sum is 44.

The square root of 121995917 is about 11045.1761869153. The cubic root of 121995917 is about 495.9620334384.

The spelling of 121995917 in words is "one hundred twenty-one million, nine hundred ninety-five thousand, nine hundred seventeen".