19666749371 has 2 divisors, whose sum is σ = 19666749372. Its totient is φ = 19666749370.

The previous prime is 19666749343. The next prime is 19666749397. The reversal of 19666749371 is 17394766691.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19666749371 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19666749371.

It is not a weakly prime, because it can be changed into another prime (19666749331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9833374685 + 9833374686.

It is an arithmetic number, because the mean of its divisors is an integer number (9833374686).

Almost surely, 2^19666749371 is an apocalyptic number.

19666749371 is a deficient number, since it is larger than the sum of its proper divisors (1).

19666749371 is an equidigital number, since it uses as much as digits as its factorization.

19666749371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10287648, while the sum is 59.

The spelling of 19666749371 in words is "nineteen billion, six hundred sixty-six million, seven hundred forty-nine thousand, three hundred seventy-one".