121889309 has 2 divisors, whose sum is σ = 121889310. Its totient is φ = 121889308.

The previous prime is 121889279. The next prime is 121889323. The reversal of 121889309 is 903988121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95981209 + 25908100 = 9797^2 + 5090^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121889309 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121889329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60944654 + 60944655.

It is an arithmetic number, because the mean of its divisors is an integer number (60944655).

Almost surely, 2^121889309 is an apocalyptic number.

It is an amenable number.

121889309 is a deficient number, since it is larger than the sum of its proper divisors (1).

121889309 is an equidigital number, since it uses as much as digits as its factorization.

121889309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 121889309 is about 11040.3491339722. The cubic root of 121889309 is about 495.8175233305.

The spelling of 121889309 in words is "one hundred twenty-one million, eight hundred eighty-nine thousand, three hundred nine".