121988869 has 4 divisors (see below), whose sum is σ = 122011596. Its totient is φ = 121966144.

The previous prime is 121988857. The next prime is 121988887. The reversal of 121988869 is 968889121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 968889121 = 28109 ⋅34469.

It can be written as a sum of positive squares in 2 ways, for example, as 9840769 + 112148100 = 3137^2 + 10590^2 .

It is a cyclic number.

It is not a de Polignac number, because 121988869 - 2²³ = 113600261 is a prime.

It is a super-2 number, since 2×121988869² = 29762568319798322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121988369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1677 + ... + 15709.

It is an arithmetic number, because the mean of its divisors is an integer number (30502899).

Almost surely, 2^121988869 is an apocalyptic number.

It is an amenable number.

121988869 is a deficient number, since it is larger than the sum of its proper divisors (22727).

121988869 is an equidigital number, since it uses as much as digits as its factorization.

121988869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22726.

The product of its digits is 497664, while the sum is 52.

The square root of 121988869 is about 11044.8571289990. The cubic root of 121988869 is about 495.9524822780.

The spelling of 121988869 in words is "one hundred twenty-one million, nine hundred eighty-eight thousand, eight hundred sixty-nine".