19963787897 has 2 divisors, whose sum is σ = 19963787898. Its totient is φ = 19963787896.

The previous prime is 19963787813. The next prime is 19963787903. The reversal of 19963787897 is 79878736991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19949867536 + 13920361 = 141244^2 + 3731^2 .

It is a cyclic number.

It is not a de Polignac number, because 19963787897 - 2¹⁸ = 19963525753 is a prime.

It is not a weakly prime, because it can be changed into another prime (19963787197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9981893948 + 9981893949.

It is an arithmetic number, because the mean of its divisors is an integer number (9981893949).

Almost surely, 2^19963787897 is an apocalyptic number.

It is an amenable number.

19963787897 is a deficient number, since it is larger than the sum of its proper divisors (1).

19963787897 is an equidigital number, since it uses as much as digits as its factorization.

19963787897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288054144, while the sum is 74.

The spelling of 19963787897 in words is "nineteen billion, nine hundred sixty-three million, seven hundred eighty-seven thousand, eight hundred ninety-seven".