999987943609 has 2 divisors, whose sum is σ = 999987943610. Its totient is φ = 999987943608.

The previous prime is 999987943501. The next prime is 999987943649. The reversal of 999987943609 is 906349789999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660830797225 + 339157146384 = 812915^2 + 582372^2 .

It is a cyclic number.

It is not a de Polignac number, because 999987943609 - 2³¹ = 997840459961 is a prime.

It is not a weakly prime, because it can be changed into another prime (999987943649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499993971804 + 499993971805.

It is an arithmetic number, because the mean of its divisors is an integer number (499993971805).

Almost surely, 2^999987943609 is an apocalyptic number.

It is an amenable number.

999987943609 is a deficient number, since it is larger than the sum of its proper divisors (1).

999987943609 is an equidigital number, since it uses as much as digits as its factorization.

999987943609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2142770112, while the sum is 82.

The spelling of 999987943609 in words is "nine hundred ninety-nine billion, nine hundred eighty-seven million, nine hundred forty-three thousand, six hundred nine".