121221010209869 has 2 divisors, whose sum is σ = 121221010209870. Its totient is φ = 121221010209868.

The previous prime is 121221010209857. The next prime is 121221010209877. The reversal of 121221010209869 is 968902010122121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78174774722500 + 43046235487369 = 8841650^2 + 6560963^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121221010209869 is a prime.

It is a super-2 number, since 2×121221010209869² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221010209889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610505104934 + 60610505104935.

It is an arithmetic number, because the mean of its divisors is an integer number (60610505104935).

Almost surely, 2^{121221010209869} is an apocalyptic number.

It is an amenable number.

121221010209869 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221010209869 is an equidigital number, since it uses as much as digits as its factorization.

121221010209869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 44.

The spelling of 121221010209869 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, ten million, two hundred nine thousand, eight hundred sixty-nine".