121221121997 has 2 divisors, whose sum is σ = 121221121998. Its totient is φ = 121221121996.

The previous prime is 121221121951. The next prime is 121221122021. The reversal of 121221121997 is 799121122121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100155792676 + 21065329321 = 316474^2 + 145139^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221121997 - 2¹⁴ = 121221105613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121221121997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221121907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610560998 + 60610560999.

It is an arithmetic number, because the mean of its divisors is an integer number (60610560999).

Almost surely, 2^121221121997 is an apocalyptic number.

It is an amenable number.

121221121997 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221121997 is an equidigital number, since it uses as much as digits as its factorization.

121221121997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 38.

The spelling of 121221121997 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-one thousand, nine hundred ninety-seven".