16688281 has 2 divisors, whose sum is σ = 16688282. Its totient is φ = 16688280.

The previous prime is 16688263. The next prime is 16688299. The reversal of 16688281 is 18288661.

It is a balanced prime because it is at equal distance from previous prime (16688263) and next prime (16688299).

It can be written as a sum of positive squares in only one way, i.e., 13505625 + 3182656 = 3675^2 + 1784^2 .

It is a cyclic number.

It is not a de Polignac number, because 16688281 - 2⁵ = 16688249 is a prime.

It is a super-2 number, since 2×16688281² = 556997445469922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16688081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8344140 + 8344141.

It is an arithmetic number, because the mean of its divisors is an integer number (8344141).

Almost surely, 2^16688281 is an apocalyptic number.

It is an amenable number.

16688281 is a deficient number, since it is larger than the sum of its proper divisors (1).

16688281 is an equidigital number, since it uses as much as digits as its factorization.

16688281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36864, while the sum is 40.

The square root of 16688281 is about 4085.1292513212. The cubic root of 16688281 is about 255.5468515484.

The spelling of 16688281 in words is "sixteen million, six hundred eighty-eight thousand, two hundred eighty-one".