199681663 has 2 divisors, whose sum is σ = 199681664. Its totient is φ = 199681662.

The previous prime is 199681619. The next prime is 199681667. The reversal of 199681663 is 366186991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199681663 - 2¹⁷ = 199550591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199681667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99840831 + 99840832.

It is an arithmetic number, because the mean of its divisors is an integer number (99840832).

Almost surely, 2^199681663 is an apocalyptic number.

199681663 is a deficient number, since it is larger than the sum of its proper divisors (1).

199681663 is an equidigital number, since it uses as much as digits as its factorization.

199681663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 49.

The square root of 199681663 is about 14130.8762290242. The cubic root of 199681663 is about 584.4931085323.

The spelling of 199681663 in words is "one hundred ninety-nine million, six hundred eighty-one thousand, six hundred sixty-three".