121221002891 has 2 divisors, whose sum is σ = 121221002892. Its totient is φ = 121221002890.

The previous prime is 121221002857. The next prime is 121221002963. The reversal of 121221002891 is 198200122121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121221002891 - 2²⁶ = 121153894027 is a prime.

It is not a weakly prime, because it can be changed into another prime (121221002491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610501445 + 60610501446.

It is an arithmetic number, because the mean of its divisors is an integer number (60610501446).

Almost surely, 2^121221002891 is an apocalyptic number.

121221002891 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221002891 is an equidigital number, since it uses as much as digits as its factorization.

121221002891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 121221002891 in words is "one hundred twenty-one billion, two hundred twenty-one million, two thousand, eight hundred ninety-one".