19829681 has 2 divisors, whose sum is σ = 19829682. Its totient is φ = 19829680.

The previous prime is 19829639. The next prime is 19829683. The reversal of 19829681 is 18692891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16679056 + 3150625 = 4084^2 + 1775^2 .

It is a cyclic number.

It is not a de Polignac number, because 19829681 - 2⁶ = 19829617 is a prime.

It is a super-2 number, since 2×19829681² = 786432497123522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 19829683, 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 (19829683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9914840 + 9914841.

It is an arithmetic number, because the mean of its divisors is an integer number (9914841).

Almost surely, 2^19829681 is an apocalyptic number.

It is an amenable number.

19829681 is a deficient number, since it is larger than the sum of its proper divisors (1).

19829681 is an equidigital number, since it uses as much as digits as its factorization.

19829681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 44.

The square root of 19829681 is about 4453.0529976635. The cubic root of 19829681 is about 270.6690358358.

The spelling of 19829681 in words is "nineteen million, eight hundred twenty-nine thousand, six hundred eighty-one".