121090891 has 2 divisors, whose sum is σ = 121090892. Its totient is φ = 121090890.

The previous prime is 121090877. The next prime is 121090897. The reversal of 121090891 is 198090121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121090891 - 2⁹ = 121090379 is a prime.

It is not a weakly prime, because it can be changed into another prime (121090897) 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 as a sum of consecutive naturals, namely, 60545445 + 60545446.

It is an arithmetic number, because the mean of its divisors is an integer number (60545446).

Almost surely, 2^121090891 is an apocalyptic number.

121090891 is a deficient number, since it is larger than the sum of its proper divisors (1).

121090891 is an equidigital number, since it uses as much as digits as its factorization.

121090891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 121090891 is about 11004.1306335394. The cubic root of 121090891 is about 494.7325576355.

The spelling of 121090891 in words is "one hundred twenty-one million, ninety thousand, eight hundred ninety-one".