17121409 has 2 divisors, whose sum is σ = 17121410. Its totient is φ = 17121408.

The previous prime is 17121389. The next prime is 17121427. The reversal of 17121409 is 90412171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16581184 + 540225 = 4072^2 + 735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17121409 is a prime.

It is a super-2 number, since 2×17121409² = 586285292290562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (17121449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8560704 + 8560705.

It is an arithmetic number, because the mean of its divisors is an integer number (8560705).

Almost surely, 2^17121409 is an apocalyptic number.

It is an amenable number.

17121409 is a deficient number, since it is larger than the sum of its proper divisors (1).

17121409 is an equidigital number, since it uses as much as digits as its factorization.

17121409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 17121409 is about 4137.8024360764. The cubic root of 17121409 is about 257.7388188759.

The spelling of 17121409 in words is "seventeen million, one hundred twenty-one thousand, four hundred nine".