121619909 has 8 divisors (see below), whose sum is σ = 124452600. Its totient is φ = 118814400.

The previous prime is 121619863. The next prime is 121619917. The reversal of 121619909 is 909916121.

It can be written as a sum of positive squares in 4 ways, for example, as 13667809 + 107952100 = 3697^2 + 10390^2 .

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 121619909 - 2¹⁶ = 121554373 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 (121619959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2399 + ... + 15779.

It is an arithmetic number, because the mean of its divisors is an integer number (15556575).

Almost surely, 2^121619909 is an apocalyptic number.

It is an amenable number.

121619909 is a deficient number, since it is larger than the sum of its proper divisors (2832691).

121619909 is a wasteful number, since it uses less digits than its factorization.

121619909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13591.

The product of its (nonzero) digits is 8748, while the sum is 38.

The square root of 121619909 is about 11028.1416838922. The cubic root of 121619909 is about 495.4519682466.

The spelling of 121619909 in words is "one hundred twenty-one million, six hundred nineteen thousand, nine hundred nine".