16591997805 has 16 divisors (see below), whose sum is σ = 26580524544. Its totient is φ = 8837956160.

The previous prime is 16591997797. The next prime is 16591997813. The reversal of 16591997805 is 50879919561.

It is an interprime number because it is at equal distance from previous prime (16591997797) and next prime (16591997813).

It is not a de Polignac number, because 16591997805 - 2³ = 16591997797 is a prime.

It is a super-2 number, since 2×16591997805² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 681981 + ... + 705890.

It is an arithmetic number, because the mean of its divisors is an integer number (1661282784).

Almost surely, 2^16591997805 is an apocalyptic number.

16591997805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16591997805 is a deficient number, since it is larger than the sum of its proper divisors (9988526739).

16591997805 is a wasteful number, since it uses less digits than its factorization.

16591997805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388676.

The product of its (nonzero) digits is 6123600, while the sum is 60.

The spelling of 16591997805 in words is "sixteen billion, five hundred ninety-one million, nine hundred ninety-seven thousand, eight hundred five".