19998926887 has 2 divisors, whose sum is σ = 19998926888. Its totient is φ = 19998926886.

The previous prime is 19998926873. The next prime is 19998926891. The reversal of 19998926887 is 78862989991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19998926887 - 2¹¹ = 19998924839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19998926587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9999463443 + 9999463444.

It is an arithmetic number, because the mean of its divisors is an integer number (9999463444).

Almost surely, 2^19998926887 is an apocalyptic number.

19998926887 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998926887 is an equidigital number, since it uses as much as digits as its factorization.

19998926887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282175488, while the sum is 76.

The spelling of 19998926887 in words is "nineteen billion, nine hundred ninety-eight million, nine hundred twenty-six thousand, eight hundred eighty-seven".