121909221 has 12 divisors (see below), whose sum is σ = 201247072. Its totient is φ = 69662376.

The previous prime is 121909219. The next prime is 121909237. The reversal of 121909221 is 122909121.

It is not a de Polignac number, because 121909221 - 2¹ = 121909219 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 (121909241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 967471 + ... + 967596.

Almost surely, 2^121909221 is an apocalyptic number.

It is an amenable number.

121909221 is a deficient number, since it is larger than the sum of its proper divisors (79337851).

121909221 is a wasteful number, since it uses less digits than its factorization.

121909221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1935080 (or 1935077 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 121909221 is about 11041.2508802219. The cubic root of 121909221 is about 495.8445209976.

The spelling of 121909221 in words is "one hundred twenty-one million, nine hundred nine thousand, two hundred twenty-one".