19736681 has 2 divisors, whose sum is σ = 19736682. Its totient is φ = 19736680.

The previous prime is 19736671. The next prime is 19736683. The reversal of 19736681 is 18663791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13690000 + 6046681 = 3700^2 + 2459^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19736681 is a prime.

It is a super-2 number, since 2×19736681² = 779073153791522, which contains 22 as substring.

Together with 19736683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19736683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9868340 + 9868341.

It is an arithmetic number, because the mean of its divisors is an integer number (9868341).

Almost surely, 2^19736681 is an apocalyptic number.

It is an amenable number.

19736681 is a deficient number, since it is larger than the sum of its proper divisors (1).

19736681 is an equidigital number, since it uses as much as digits as its factorization.

19736681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 41.

The square root of 19736681 is about 4442.5984513570. The cubic root of 19736681 is about 270.2452321574.

The spelling of 19736681 in words is "nineteen million, seven hundred thirty-six thousand, six hundred eighty-one".