16663481 has 2 divisors, whose sum is σ = 16663482. Its totient is φ = 16663480.

The previous prime is 16663469. The next prime is 16663483. The reversal of 16663481 is 18436661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10368400 + 6295081 = 3220^2 + 2509^2 .

It is a cyclic number.

It is not a de Polignac number, because 16663481 - 2¹⁸ = 16401337 is a prime.

It is a super-2 number, since 2×16663481² = 555343198074722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 16663483, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16663483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8331740 + 8331741.

It is an arithmetic number, because the mean of its divisors is an integer number (8331741).

Almost surely, 2^16663481 is an apocalyptic number.

It is an amenable number.

16663481 is a deficient number, since it is larger than the sum of its proper divisors (1).

16663481 is an equidigital number, since it uses as much as digits as its factorization.

16663481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 35.

The square root of 16663481 is about 4082.0927231017. The cubic root of 16663481 is about 255.4202017181.

The spelling of 16663481 in words is "sixteen million, six hundred sixty-three thousand, four hundred eighty-one".