121305609 has 6 divisors (see below), whose sum is σ = 175219226. Its totient is φ = 80870400.

The previous prime is 121305599. The next prime is 121305617. The reversal of 121305609 is 906503121.

121305609 is a `hidden beast` number, since 1 + 21 + 30 + 5 + 609 = 666.

It can be written as a sum of positive squares in only one way, i.e., 109935225 + 11370384 = 10485^2 + 3372^2 .

It is not a de Polignac number, because 121305609 - 2⁹ = 121305097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121305619) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6739192 + ... + 6739209.

Almost surely, 2^121305609 is an apocalyptic number.

It is an amenable number.

121305609 is a deficient number, since it is larger than the sum of its proper divisors (53913617).

121305609 is a wasteful number, since it uses less digits than its factorization.

121305609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13478407 (or 13478404 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 121305609 is about 11013.8825579357. The cubic root of 121305609 is about 495.0248043891.

The spelling of 121305609 in words is "one hundred twenty-one million, three hundred five thousand, six hundred nine".