121220989 has 4 divisors (see below), whose sum is σ = 121692924. Its totient is φ = 120749056.

The previous prime is 121220963. The next prime is 121220993. The reversal of 121220989 is 989022121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 989022121 = 509 ⋅1943069.

It can be written as a sum of positive squares in 2 ways, for example, as 75116889 + 46104100 = 8667^2 + 6790^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220989 - 2⁷ = 121220861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220389) 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, 235582 + ... + 236095.

It is an arithmetic number, because the mean of its divisors is an integer number (30423231).

Almost surely, 2^121220989 is an apocalyptic number.

It is an amenable number.

121220989 is a deficient number, since it is larger than the sum of its proper divisors (471935).

121220989 is an equidigital number, since it uses as much as digits as its factorization.

121220989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471934.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 121220989 is about 11010.0403723147. The cubic root of 121220989 is about 494.9096716448.

It can be divided in two parts, 1212 and 20989, that added together give a square (22201 = 149²).

The spelling of 121220989 in words is "one hundred twenty-one million, two hundred twenty thousand, nine hundred eighty-nine".