19871423893 has 2 divisors, whose sum is σ = 19871423894. Its totient is φ = 19871423892.

The previous prime is 19871423857. The next prime is 19871423909. The reversal of 19871423893 is 39832417891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10318902724 + 9552521169 = 101582^2 + 97737^2 .

It is a cyclic number.

It is not a de Polignac number, because 19871423893 - 2⁹ = 19871423381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19871423813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9935711946 + 9935711947.

It is an arithmetic number, because the mean of its divisors is an integer number (9935711947).

Almost surely, 2^19871423893 is an apocalyptic number.

It is an amenable number.

19871423893 is a deficient number, since it is larger than the sum of its proper divisors (1).

19871423893 is an equidigital number, since it uses as much as digits as its factorization.

19871423893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 55.

The spelling of 19871423893 in words is "nineteen billion, eight hundred seventy-one million, four hundred twenty-three thousand, eight hundred ninety-three".