121389 has 8 divisors (see below), whose sum is σ = 165792. Its totient is φ = 78960.

The previous prime is 121379. The next prime is 121403. The reversal of 121389 is 983121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121389 - 2⁵ = 121357 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

121389 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342 + ... + 599.

It is an arithmetic number, because the mean of its divisors is an integer number (20724).

2¹²¹³⁸⁹ is an apocalyptic number.

It is an amenable number.

121389 is a deficient number, since it is larger than the sum of its proper divisors (44403).

121389 is an equidigital number, since it uses as much as digits as its factorization.

121389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987.

The product of its digits is 432, while the sum is 24.

The square root of 121389 is about 348.4092421277. The cubic root of 121389 is about 49.5138212604.

The spelling of 121389 in words is "one hundred twenty-one thousand, three hundred eighty-nine".