17281981 has 2 divisors, whose sum is σ = 17281982. Its totient is φ = 17281980.

The previous prime is 17281969. The next prime is 17281987. The reversal of 17281981 is 18918271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17264025 + 17956 = 4155^2 + 134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17281981 is a prime.

It is a super-2 number, since 2×17281981² = 597333734568722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 17281981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17281987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8640990 + 8640991.

It is an arithmetic number, because the mean of its divisors is an integer number (8640991).

Almost surely, 2^17281981 is an apocalyptic number.

It is an amenable number.

17281981 is a deficient number, since it is larger than the sum of its proper divisors (1).

17281981 is an equidigital number, since it uses as much as digits as its factorization.

17281981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 37.

The square root of 17281981 is about 4157.1602086039. The cubic root of 17281981 is about 258.5420419058.

The spelling of 17281981 in words is "seventeen million, two hundred eighty-one thousand, nine hundred eighty-one".