121995979 has 24 divisors (see below), whose sum is σ = 153619200. Its totient is φ = 94712112.

The previous prime is 121995971. The next prime is 121996001. The reversal of 121995979 is 979599121.

It is a happy number.

It is not a de Polignac number, because 121995979 - 2³ = 121995971 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (121995971) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 57072 + ... + 59170.

It is an arithmetic number, because the mean of its divisors is an integer number (6400800).

Almost surely, 2^121995979 is an apocalyptic number.

121995979 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

121995979 is a deficient number, since it is larger than the sum of its proper divisors (31623221).

121995979 is a wasteful number, since it uses less digits than its factorization.

121995979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2167 (or 2148 counting only the distinct ones).

The product of its digits is 459270, while the sum is 52.

The square root of 121995979 is about 11045.1789935700. The cubic root of 121995979 is about 495.9621174566.

It can be divided in two parts, 12 and 1995979, that added together give a palindrome (1995991).

The spelling of 121995979 in words is "one hundred twenty-one million, nine hundred ninety-five thousand, nine hundred seventy-nine".