121205717 has 4 divisors (see below), whose sum is σ = 124161996. Its totient is φ = 118249440.

The previous prime is 121205683. The next prime is 121205723. The reversal of 121205717 is 717502121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16532356 + 104673361 = 4066^2 + 10231^2 .

It is a cyclic number.

It is not a de Polignac number, because 121205717 - 2¹⁴ = 121189333 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 (121205797) 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 3 ways as a sum of consecutive naturals, for example, 1478078 + ... + 1478159.

It is an arithmetic number, because the mean of its divisors is an integer number (31040499).

Almost surely, 2^121205717 is an apocalyptic number.

It is an amenable number.

121205717 is a deficient number, since it is larger than the sum of its proper divisors (2956279).

121205717 is an equidigital number, since it uses as much as digits as its factorization.

121205717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2956278.

The product of its (nonzero) digits is 980, while the sum is 26.

The square root of 121205717 is about 11009.3468016954. The cubic root of 121205717 is about 494.8888870761. Note that the first 5 decimals are identical.

Adding to 121205717 its reverse (717502121), we get a palindrome (838707838).

The spelling of 121205717 in words is "one hundred twenty-one million, two hundred five thousand, seven hundred seventeen".