121721615207 has 4 divisors (see below), whose sum is σ = 122926779816. Its totient is φ = 120516450600.

The previous prime is 121721615077. The next prime is 121721615209. The reversal of 121721615207 is 702516127121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121721615207 - 2¹⁶ = 121721549671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121721615209) 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, 602582153 + ... + 602582354.

It is an arithmetic number, because the mean of its divisors is an integer number (30731694954).

Almost surely, 2^121721615207 is an apocalyptic number.

121721615207 is a deficient number, since it is larger than the sum of its proper divisors (1205164609).

121721615207 is a wasteful number, since it uses less digits than its factorization.

121721615207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1205164608.

The product of its (nonzero) digits is 11760, while the sum is 35.

The spelling of 121721615207 in words is "one hundred twenty-one billion, seven hundred twenty-one million, six hundred fifteen thousand, two hundred seven".