121972909 has 16 divisors (see below), whose sum is σ = 133660800. Its totient is φ = 110845440.

The previous prime is 121972891. The next prime is 121972967. The reversal of 121972909 is 909279121.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-121972909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121972969) 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 15 ways as a sum of consecutive naturals, for example, 70942 + ... + 72640.

It is an arithmetic number, because the mean of its divisors is an integer number (8353800).

Almost surely, 2^121972909 is an apocalyptic number.

It is an amenable number.

121972909 is a deficient number, since it is larger than the sum of its proper divisors (11687891).

121972909 is a wasteful number, since it uses less digits than its factorization.

121972909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1860.

The product of its (nonzero) digits is 20412, while the sum is 40.

The square root of 121972909 is about 11044.1345971516. The cubic root of 121972909 is about 495.9308525809.

The spelling of 121972909 in words is "one hundred twenty-one million, nine hundred seventy-two thousand, nine hundred nine".