121778717 has 2 divisors, whose sum is σ = 121778718. Its totient is φ = 121778716.

The previous prime is 121778693. The next prime is 121778719. The reversal of 121778717 is 717877121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121638841 + 139876 = 11029^2 + 374^2 .

It is a cyclic number.

It is not a de Polignac number, because 121778717 - 2⁶ = 121778653 is a prime.

Together with 121778719, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121778719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60889358 + 60889359.

It is an arithmetic number, because the mean of its divisors is an integer number (60889359).

Almost surely, 2^121778717 is an apocalyptic number.

It is an amenable number.

121778717 is a deficient number, since it is larger than the sum of its proper divisors (1).

121778717 is an equidigital number, since it uses as much as digits as its factorization.

121778717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38416, while the sum is 41.

The square root of 121778717 is about 11035.3394601163. The cubic root of 121778717 is about 495.6675237282.

The spelling of 121778717 in words is "one hundred twenty-one million, seven hundred seventy-eight thousand, seven hundred seventeen".