121391305 has 16 divisors (see below), whose sum is σ = 176273280. Its totient is φ = 78342912.

The previous prime is 121391293. The next prime is 121391317. The reversal of 121391305 is 503193121.

It is an interprime number because it is at equal distance from previous prime (121391293) and next prime (121391317).

It is a cyclic number.

It is not a de Polignac number, because 121391305 - 2¹⁷ = 121260233 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121391305.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 101415 + ... + 102604.

It is an arithmetic number, because the mean of its divisors is an integer number (11017080).

Almost surely, 2^121391305 is an apocalyptic number.

It is an amenable number.

121391305 is a deficient number, since it is larger than the sum of its proper divisors (54881975).

121391305 is a wasteful number, since it uses less digits than its factorization.

121391305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204048.

The product of its (nonzero) digits is 810, while the sum is 25.

The square root of 121391305 is about 11017.7722339863. The cubic root of 121391305 is about 495.1413465681.

The spelling of 121391305 in words is "one hundred twenty-one million, three hundred ninety-one thousand, three hundred five".