121661221 has 8 divisors (see below), whose sum is σ = 132804000. Its totient is φ = 110532240.

The previous prime is 121661219. The next prime is 121661251. The reversal of 121661221 is 122166121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121661221 - 2¹ = 121661219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121661192 and 121661201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121661201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25870 + ... + 30208.

It is an arithmetic number, because the mean of its divisors is an integer number (16600500).

Almost surely, 2^121661221 is an apocalyptic number.

121661221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121661221 is a deficient number, since it is larger than the sum of its proper divisors (11142779).

121661221 is a wasteful number, since it uses less digits than its factorization.

121661221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6899.

The product of its digits is 288, while the sum is 22.

The square root of 121661221 is about 11030.0145512143. The cubic root of 121661221 is about 495.5080604735.

The spelling of 121661221 in words is "one hundred twenty-one million, six hundred sixty-one thousand, two hundred twenty-one".