121660221 has 4 divisors (see below), whose sum is σ = 162213632. Its totient is φ = 81106812.

The previous prime is 121660199. The next prime is 121660223. The reversal of 121660221 is 122066121.

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 not a de Polignac number, because 121660221 - 2⁹ = 121659709 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 (121660223) 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 3 ways as a sum of consecutive naturals, for example, 20276701 + ... + 20276706.

It is an arithmetic number, because the mean of its divisors is an integer number (40553408).

Almost surely, 2^121660221 is an apocalyptic number.

It is an amenable number.

121660221 is a deficient number, since it is larger than the sum of its proper divisors (40553411).

121660221 is an equidigital number, since it uses as much as digits as its factorization.

121660221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40553410.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 121660221 is about 11029.9692202653. The cubic root of 121660221 is about 495.5067028527.

The spelling of 121660221 in words is "one hundred twenty-one million, six hundred sixty thousand, two hundred twenty-one".