999997999805 has 48 divisors (see below), whose sum is σ = 1403361552384. Its totient is φ = 682065095040.

The previous prime is 999997999799. The next prime is 999997999811. The reversal of 999997999805 is 508999799999.

999997999805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (999997999799) and next prime (999997999811).

It is not a de Polignac number, because 999997999805 - 2⁸ = 999997999549 is a prime.

It is a super-2 number, since 2×999997999805² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 34986170 + ... + 35014740.

It is an arithmetic number, because the mean of its divisors is an integer number (29236699008).

Almost surely, 2^999997999805 is an apocalyptic number.

It is an amenable number.

999997999805 is a deficient number, since it is larger than the sum of its proper divisors (403363552579).

999997999805 is a wasteful number, since it uses less digits than its factorization.

999997999805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29346 (or 29339 counting only the distinct ones).

The product of its (nonzero) digits is 12053081880, while the sum is 92.

The spelling of 999997999805 in words is "nine hundred ninety-nine billion, nine hundred ninety-seven million, nine hundred ninety-nine thousand, eight hundred five".