121399121 has 4 divisors (see below), whose sum is σ = 121468992. Its totient is φ = 121329252.

The previous prime is 121399111. The next prime is 121399153. The reversal of 121399121 is 121993121.

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, and also an emirpimes, since its reverse is a distinct semiprime: 121993121 = 53 ⋅2301757.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121399121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121399111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32261 + ... + 35826.

It is an arithmetic number, because the mean of its divisors is an integer number (30367248).

Almost surely, 2^121399121 is an apocalyptic number.

It is an amenable number.

121399121 is a deficient number, since it is larger than the sum of its proper divisors (69871).

121399121 is an equidigital number, since it uses as much as digits as its factorization.

121399121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69870.

The product of its digits is 972, while the sum is 29.

The square root of 121399121 is about 11018.1269279311. The cubic root of 121399121 is about 495.1519731989.

The spelling of 121399121 in words is "one hundred twenty-one million, three hundred ninety-nine thousand, one hundred twenty-one".