121721209223 has 2 divisors, whose sum is σ = 121721209224. Its totient is φ = 121721209222.

The previous prime is 121721209157. The next prime is 121721209243. The reversal of 121721209223 is 322902127121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121721209223 - 2¹² = 121721205127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121721209223.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121721209243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60860604611 + 60860604612.

It is an arithmetic number, because the mean of its divisors is an integer number (60860604612).

Almost surely, 2^121721209223 is an apocalyptic number.

121721209223 is a deficient number, since it is larger than the sum of its proper divisors (1).

121721209223 is an equidigital number, since it uses as much as digits as its factorization.

121721209223 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The spelling of 121721209223 in words is "one hundred twenty-one billion, seven hundred twenty-one million, two hundred nine thousand, two hundred twenty-three".