999999987893 has 2 divisors, whose sum is σ = 999999987894. Its totient is φ = 999999987892.

The previous prime is 999999987827. The next prime is 999999987919. The reversal of 999999987893 is 398789999999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 987195254929 + 12804732964 = 993577^2 + 113158^2 .

It is a cyclic number.

It is not a de Polignac number, because 999999987893 - 2¹⁸ = 999999725749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999999987893.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999999989893) 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, 499999993946 + 499999993947.

It is an arithmetic number, because the mean of its divisors is an integer number (499999993947).

Almost surely, 2^999999987893 is an apocalyptic number.

It is an amenable number.

999999987893 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999987893 is an equidigital number, since it uses as much as digits as its factorization.

999999987893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57854793024, while the sum is 98.

The spelling of 999999987893 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred eighty-seven thousand, eight hundred ninety-three".