121980689 has 2 divisors, whose sum is σ = 121980690. Its totient is φ = 121980688.

The previous prime is 121980667. The next prime is 121980713. The reversal of 121980689 is 986089121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90250000 + 31730689 = 9500^2 + 5633^2 .

It is an emirp because it is prime and its reverse (986089121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121980689 - 2¹² = 121976593 is a prime.

It is not a weakly prime, because it can be changed into another prime (121980659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60990344 + 60990345.

It is an arithmetic number, because the mean of its divisors is an integer number (60990345).

Almost surely, 2^121980689 is an apocalyptic number.

It is an amenable number.

121980689 is a deficient number, since it is larger than the sum of its proper divisors (1).

121980689 is an equidigital number, since it uses as much as digits as its factorization.

121980689 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 square root of 121980689 is about 11044.4868146963. The cubic root of 121980689 is about 495.9413966163.

The spelling of 121980689 in words is "one hundred twenty-one million, nine hundred eighty thousand, six hundred eighty-nine".