121913217 has 12 divisors (see below), whose sum is σ = 176193940. Its totient is φ = 81230688.

The previous prime is 121913203. The next prime is 121913219. The reversal of 121913217 is 712319121.

It can be written as a sum of positive squares in 2 ways, for example, as 84934656 + 36978561 = 9216^2 + 6081^2 .

It is not a de Polignac number, because 121913217 - 2¹⁵ = 121880449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121913219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25803 + ... + 30159.

Almost surely, 2^121913217 is an apocalyptic number.

It is an amenable number.

121913217 is a deficient number, since it is larger than the sum of its proper divisors (54280723).

121913217 is a wasteful number, since it uses less digits than its factorization.

121913217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7472 (or 7469 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 121913217 is about 11041.4318364966. The cubic root of 121913217 is about 495.8499386164.

The spelling of 121913217 in words is "one hundred twenty-one million, nine hundred thirteen thousand, two hundred seventeen".