121211200091 has 2 divisors, whose sum is σ = 121211200092. Its totient is φ = 121211200090.

The previous prime is 121211200069. The next prime is 121211200109. The reversal of 121211200091 is 190002112121.

Together with next prime (121211200109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121211200091 is a prime.

It is not a weakly prime, because it can be changed into another prime (121211200051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605600045 + 60605600046.

It is an arithmetic number, because the mean of its divisors is an integer number (60605600046).

Almost surely, 2^121211200091 is an apocalyptic number.

121211200091 is a deficient number, since it is larger than the sum of its proper divisors (1).

121211200091 is an equidigital number, since it uses as much as digits as its factorization.

121211200091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 121211200091 in words is "one hundred twenty-one billion, two hundred eleven million, two hundred thousand, ninety-one".