805640861555 has 32 divisors (see below), whose sum is σ = 1026041784768. Its totient is φ = 605176934400.

The previous prime is 805640861539. The next prime is 805640861561. The reversal of 805640861555 is 555168046508.

It is not a de Polignac number, because 805640861555 - 2⁴ = 805640861539 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 805640861497 and 805640861506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 103909559 + ... + 103917311.

It is an arithmetic number, because the mean of its divisors is an integer number (32063805774).

Almost surely, 2^805640861555 is an apocalyptic number.

805640861555 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

805640861555 is a deficient number, since it is larger than the sum of its proper divisors (220400923213).

805640861555 is a wasteful number, since it uses less digits than its factorization.

805640861555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10487.

The product of its (nonzero) digits is 5760000, while the sum is 53.

The spelling of 805640861555 in words is "eight hundred five billion, six hundred forty million, eight hundred sixty-one thousand, five hundred fifty-five".