16705681 has 2 divisors, whose sum is σ = 16705682. Its totient is φ = 16705680.

The previous prime is 16705657. The next prime is 16705687. The reversal of 16705681 is 18650761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14318656 + 2387025 = 3784^2 + 1545^2 .

It is a cyclic number.

It is not a de Polignac number, because 16705681 - 2⁷ = 16705553 is a prime.

It is a super-2 number, since 2×16705681² = 558159555347522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16705687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8352840 + 8352841.

It is an arithmetic number, because the mean of its divisors is an integer number (8352841).

Almost surely, 2^16705681 is an apocalyptic number.

It is an amenable number.

16705681 is a deficient number, since it is larger than the sum of its proper divisors (1).

16705681 is an equidigital number, since it uses as much as digits as its factorization.

16705681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 16705681 is about 4087.2583720631. The cubic root of 16705681 is about 255.6356358222.

The spelling of 16705681 in words is "sixteen million, seven hundred five thousand, six hundred eighty-one".