17320421 has 2 divisors, whose sum is σ = 17320422. Its totient is φ = 17320420.

The previous prime is 17320349. The next prime is 17320439. The reversal of 17320421 is 12402371.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16240900 + 1079521 = 4030^2 + 1039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17320421 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 17320393 and 17320402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17320441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8660210 + 8660211.

It is an arithmetic number, because the mean of its divisors is an integer number (8660211).

Almost surely, 2^17320421 is an apocalyptic number.

It is an amenable number.

17320421 is a deficient number, since it is larger than the sum of its proper divisors (1).

17320421 is an equidigital number, since it uses as much as digits as its factorization.

17320421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 17320421 is about 4161.7809889517. The cubic root of 17320421 is about 258.7335900972.

Adding to 17320421 its reverse (12402371), we get a palindrome (29722792).

The spelling of 17320421 in words is "seventeen million, three hundred twenty thousand, four hundred twenty-one".