805405811691 has 32 divisors (see below), whose sum is σ = 1162490337792. Its totient is φ = 493064881920.

The previous prime is 805405811663. The next prime is 805405811753. The reversal of 805405811691 is 196118504508.

It is not a de Polignac number, because 805405811691 - 2¹⁵ = 805405778923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 805405811691.

It is not an unprimeable number, because it can be changed into a prime (805405811491) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6074536 + ... + 6205706.

It is an arithmetic number, because the mean of its divisors is an integer number (36327823056).

Almost surely, 2^805405811691 is an apocalyptic number.

805405811691 is a deficient number, since it is larger than the sum of its proper divisors (357084526101).

805405811691 is a wasteful number, since it uses less digits than its factorization.

805405811691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132003.

The product of its (nonzero) digits is 345600, while the sum is 48.

The spelling of 805405811691 in words is "eight hundred five billion, four hundred five million, eight hundred eleven thousand, six hundred ninety-one".