121716389 has 2 divisors, whose sum is σ = 121716390. Its totient is φ = 121716388.

The previous prime is 121716383. The next prime is 121716407. The reversal of 121716389 is 983617121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117007489 + 4708900 = 10817^2 + 2170^2 .

It is an emirp because it is prime and its reverse (983617121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121716389 - 2⁴ = 121716373 is a prime.

It is a Chen prime.

It is equal to p_6933791 and since 121716389 and 6933791 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121716383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60858194 + 60858195.

It is an arithmetic number, because the mean of its divisors is an integer number (60858195).

Almost surely, 2^121716389 is an apocalyptic number.

It is an amenable number.

121716389 is a deficient number, since it is larger than the sum of its proper divisors (1).

121716389 is an equidigital number, since it uses as much as digits as its factorization.

121716389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 121716389 is about 11032.5150804338. The cubic root of 121716389 is about 495.5829461755.

The spelling of 121716389 in words is "one hundred twenty-one million, seven hundred sixteen thousand, three hundred eighty-nine".