121439 has 2 divisors, whose sum is σ = 121440. Its totient is φ = 121438.

The previous prime is 121421. The next prime is 121441. The reversal of 121439 is 934121.

It is a strong prime.

It is an emirp because it is prime and its reverse (934121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121439 - 2¹⁶ = 55903 is a prime.

Together with 121441, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121439.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 121439.

It is not a weakly prime, because it can be changed into another prime (121469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60719 + 60720.

It is an arithmetic number, because the mean of its divisors is an integer number (60720).

2¹²¹⁴³⁹ is an apocalyptic number.

121439 is a deficient number, since it is larger than the sum of its proper divisors (1).

121439 is an equidigital number, since it uses as much as digits as its factorization.

121439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

The square root of 121439 is about 348.4809894384. The cubic root of 121439 is about 49.5206185573.

The spelling of 121439 in words is "one hundred twenty-one thousand, four hundred thirty-nine".