17131921 has 2 divisors, whose sum is σ = 17131922. Its totient is φ = 17131920.

The previous prime is 17131909. The next prime is 17131943. The reversal of 17131921 is 12913171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12006225 + 5125696 = 3465^2 + 2264^2 .

It is an emirp because it is prime and its reverse (12913171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 17131921 - 2⁹ = 17131409 is a prime.

It is not a weakly prime, because it can be changed into another prime (17131981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8565960 + 8565961.

It is an arithmetic number, because the mean of its divisors is an integer number (8565961).

Almost surely, 2^17131921 is an apocalyptic number.

It is an amenable number.

17131921 is a deficient number, since it is larger than the sum of its proper divisors (1).

17131921 is an equidigital number, since it uses as much as digits as its factorization.

17131921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 378, while the sum is 25.

The square root of 17131921 is about 4139.0724806410. The cubic root of 17131921 is about 257.7915558939.

The spelling of 17131921 in words is "seventeen million, one hundred thirty-one thousand, nine hundred twenty-one".