121021211917 has 2 divisors, whose sum is σ = 121021211918. Its totient is φ = 121021211916.

The previous prime is 121021211887. The next prime is 121021212019. The reversal of 121021211917 is 719112120121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108617044041 + 12404167876 = 329571^2 + 111374^2 .

It is a cyclic number.

It is not a de Polignac number, because 121021211917 - 2¹⁹ = 121020687629 is a prime.

It is a super-2 number, since 2×121021211917² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121021211317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60510605958 + 60510605959.

It is an arithmetic number, because the mean of its divisors is an integer number (60510605959).

Almost surely, 2^121021211917 is an apocalyptic number.

It is an amenable number.

121021211917 is a deficient number, since it is larger than the sum of its proper divisors (1).

121021211917 is an equidigital number, since it uses as much as digits as its factorization.

121021211917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 28.

The spelling of 121021211917 in words is "one hundred twenty-one billion, twenty-one million, two hundred eleven thousand, nine hundred seventeen".