121115921 has 4 divisors (see below), whose sum is σ = 121143792. Its totient is φ = 121088052.

The previous prime is 121115909. The next prime is 121115933. The reversal of 121115921 is 129511121.

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 an interprime number because it is at equal distance from previous prime (121115909) and next prime (121115933).

It is a cyclic number.

It is not a de Polignac number, because 121115921 - 2⁶ = 121115857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121115941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5855 + ... + 16628.

It is an arithmetic number, because the mean of its divisors is an integer number (30285948).

Almost surely, 2^121115921 is an apocalyptic number.

It is an amenable number.

121115921 is a deficient number, since it is larger than the sum of its proper divisors (27871).

121115921 is an equidigital number, since it uses as much as digits as its factorization.

121115921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27870.

The product of its digits is 180, while the sum is 23.

The square root of 121115921 is about 11005.2678749770. The cubic root of 121115921 is about 494.7666430587.

The spelling of 121115921 in words is "one hundred twenty-one million, one hundred fifteen thousand, nine hundred twenty-one".