121688221 has 4 divisors (see below), whose sum is σ = 121720672. Its totient is φ = 121655772.

The previous prime is 121688213. The next prime is 121688251. The reversal of 121688221 is 122886121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121688221 - 2³ = 121688213 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 (121688251) 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, 9735 + ... + 18388.

It is an arithmetic number, because the mean of its divisors is an integer number (30430168).

Almost surely, 2^121688221 is an apocalyptic number.

It is an amenable number.

121688221 is a deficient number, since it is larger than the sum of its proper divisors (32451).

121688221 is an equidigital number, since it uses as much as digits as its factorization.

121688221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32450.

The product of its digits is 3072, while the sum is 31.

The square root of 121688221 is about 11031.2384164245. The cubic root of 121688221 is about 495.5447134238.

The spelling of 121688221 in words is "one hundred twenty-one million, six hundred eighty-eight thousand, two hundred twenty-one".