121616989 has 4 divisors (see below), whose sum is σ = 130972156. Its totient is φ = 112261824.

The previous prime is 121616969. The next prime is 121617007. The reversal of 121616989 is 989616121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30891364 + 90725625 = 5558^2 + 9525^2 .

It is a cyclic number.

It is not a de Polignac number, because 121616989 - 2⁹ = 121616477 is a prime.

It is a super-2 number, since 2×121616989² = 29581384026852242, which contains 22 as substring.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121616969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4677564 + ... + 4677589.

It is an arithmetic number, because the mean of its divisors is an integer number (32743039).

Almost surely, 2^121616989 is an apocalyptic number.

It is an amenable number.

121616989 is a deficient number, since it is larger than the sum of its proper divisors (9355167).

121616989 is an equidigital number, since it uses as much as digits as its factorization.

121616989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9355166.

The product of its digits is 46656, while the sum is 43.

The square root of 121616989 is about 11028.0092945191. The cubic root of 121616989 is about 495.4480030753.

The spelling of 121616989 in words is "one hundred twenty-one million, six hundred sixteen thousand, nine hundred eighty-nine".