121555099 has 2 divisors, whose sum is σ = 121555100. Its totient is φ = 121555098.

The previous prime is 121555081. The next prime is 121555111. The reversal of 121555099 is 990555121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121555099 - 2²³ = 113166491 is a prime.

It is not a weakly prime, because it can be changed into another prime (121555699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60777549 + 60777550.

It is an arithmetic number, because the mean of its divisors is an integer number (60777550).

Almost surely, 2^121555099 is an apocalyptic number.

121555099 is a deficient number, since it is larger than the sum of its proper divisors (1).

121555099 is an equidigital number, since it uses as much as digits as its factorization.

121555099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20250, while the sum is 37.

The square root of 121555099 is about 11025.2029006273. The cubic root of 121555099 is about 495.3639455214.

The spelling of 121555099 in words is "one hundred twenty-one million, five hundred fifty-five thousand, ninety-nine".