121721943 has 16 divisors (see below), whose sum is σ = 186667520. Its totient is φ = 69110496.

The previous prime is 121721933. The next prime is 121721947. The reversal of 121721943 is 349127121.

It is not a de Polignac number, because 121721943 - 2⁴ = 121721927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121721943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121721947) 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, 15163 + ... + 21756.

It is an arithmetic number, because the mean of its divisors is an integer number (11666720).

Almost surely, 2^121721943 is an apocalyptic number.

121721943 is a deficient number, since it is larger than the sum of its proper divisors (64945577).

121721943 is a wasteful number, since it uses less digits than its factorization.

121721943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37086.

The product of its digits is 3024, while the sum is 30.

The square root of 121721943 is about 11032.7667880727. The cubic root of 121721943 is about 495.5904839876.

The spelling of 121721943 in words is "one hundred twenty-one million, seven hundred twenty-one thousand, nine hundred forty-three".