19703681 has 2 divisors, whose sum is σ = 19703682. Its totient is φ = 19703680.

The previous prime is 19703653. The next prime is 19703683. The reversal of 19703681 is 18630791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19536400 + 167281 = 4420^2 + 409^2 .

It is an emirp because it is prime and its reverse (18630791) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19703681 is a prime.

It is a super-2 number, since 2×19703681² = 776470089899522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 19703683, 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 (19703683) 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, 9851840 + 9851841.

It is an arithmetic number, because the mean of its divisors is an integer number (9851841).

Almost surely, 2^19703681 is an apocalyptic number.

It is an amenable number.

19703681 is a deficient number, since it is larger than the sum of its proper divisors (1).

19703681 is an equidigital number, since it uses as much as digits as its factorization.

19703681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 19703681 is about 4438.8828549535. The cubic root of 19703681 is about 270.0945302287.

The spelling of 19703681 in words is "nineteen million, seven hundred three thousand, six hundred eighty-one".