121649209 has 8 divisors (see below), whose sum is σ = 134958240. Its totient is φ = 108715200.

The previous prime is 121649197. The next prime is 121649221. The reversal of 121649209 is 902946121.

It is an interprime number because it is at equal distance from previous prime (121649197) and next prime (121649221).

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

It is a de Polignac number, because none of the positive numbers 2^k-121649209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121649299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93072 + ... + 94369.

It is an arithmetic number, because the mean of its divisors is an integer number (16869780).

Almost surely, 2^121649209 is an apocalyptic number.

It is an amenable number.

121649209 is a deficient number, since it is larger than the sum of its proper divisors (13309031).

121649209 is a wasteful number, since it uses less digits than its factorization.

121649209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187511.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 121649209 is about 11029.4700235324. The cubic root of 121649209 is about 495.4917522402.

The spelling of 121649209 in words is "one hundred twenty-one million, six hundred forty-nine thousand, two hundred nine".