121290989 has 2 divisors, whose sum is σ = 121290990. Its totient is φ = 121290988.

The previous prime is 121290979. The next prime is 121291013. The reversal of 121290989 is 989092121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98346889 + 22944100 = 9917^2 + 4790^2 .

It is an emirp because it is prime and its reverse (989092121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121290989 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121290919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60645494 + 60645495.

It is an arithmetic number, because the mean of its divisors is an integer number (60645495).

Almost surely, 2^121290989 is an apocalyptic number.

It is an amenable number.

121290989 is a deficient number, since it is larger than the sum of its proper divisors (1).

121290989 is an equidigital number, since it uses as much as digits as its factorization.

121290989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 121290989 is about 11013.2188301150. The cubic root of 121290989 is about 495.0049164563.

The spelling of 121290989 in words is "one hundred twenty-one million, two hundred ninety thousand, nine hundred eighty-nine".