121716817969 has 2 divisors, whose sum is σ = 121716817970. Its totient is φ = 121716817968.

The previous prime is 121716817967. The next prime is 121716817987. The reversal of 121716817969 is 969718617121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64548007969 + 57168810000 = 254063^2 + 239100^2 .

It is a cyclic number.

It is not a de Polignac number, because 121716817969 - 2¹ = 121716817967 is a prime.

It is a super-3 number, since 3×121716817969³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 121716817967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (121716817967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60858408984 + 60858408985.

It is an arithmetic number, because the mean of its divisors is an integer number (60858408985).

Almost surely, 2^121716817969 is an apocalyptic number.

It is an amenable number.

121716817969 is a deficient number, since it is larger than the sum of its proper divisors (1).

121716817969 is an equidigital number, since it uses as much as digits as its factorization.

121716817969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 58.

The spelling of 121716817969 in words is "one hundred twenty-one billion, seven hundred sixteen million, eight hundred seventeen thousand, nine hundred sixty-nine".