121171989 has 4 divisors (see below), whose sum is σ = 161562656. Its totient is φ = 80781324.

The previous prime is 121171957. The next prime is 121171991. The reversal of 121171989 is 989171121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 121171989 - 2⁵ = 121171957 is a prime.

It is a super-2 number, since 2×121171989² = 29365301836432242, 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 (121171909) 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, 20195329 + ... + 20195334.

It is an arithmetic number, because the mean of its divisors is an integer number (40390664).

Almost surely, 2^121171989 is an apocalyptic number.

It is an amenable number.

121171989 is a deficient number, since it is larger than the sum of its proper divisors (40390667).

121171989 is an equidigital number, since it uses as much as digits as its factorization.

121171989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40390666.

The product of its digits is 9072, while the sum is 39.

The square root of 121171989 is about 11007.8149057840. The cubic root of 121171989 is about 494.8429784581.

The spelling of 121171989 in words is "one hundred twenty-one million, one hundred seventy-one thousand, nine hundred eighty-nine".