19719697 has 2 divisors, whose sum is σ = 19719698. Its totient is φ = 19719696.

The previous prime is 19719691. The next prime is 19719719. The reversal of 19719697 is 79691791.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14107536 + 5612161 = 3756^2 + 2369^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19719697 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19719697.

It is not a weakly prime, because it can be changed into another prime (19719691) 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, 9859848 + 9859849.

It is an arithmetic number, because the mean of its divisors is an integer number (9859849).

Almost surely, 2^19719697 is an apocalyptic number.

It is an amenable number.

19719697 is a deficient number, since it is larger than the sum of its proper divisors (1).

19719697 is an equidigital number, since it uses as much as digits as its factorization.

19719697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 214326, while the sum is 49.

The square root of 19719697 is about 4440.6865460197. The cubic root of 19719697 is about 270.1676918958.

The spelling of 19719697 in words is "nineteen million, seven hundred nineteen thousand, six hundred ninety-seven".