805999951 has 4 divisors (see below), whose sum is σ = 806080752. Its totient is φ = 805919152.

The previous prime is 805999939. The next prime is 805999963. The reversal of 805999951 is 159999508.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (805999939) and next prime (805999963).

It is a cyclic number.

It is not a de Polignac number, because 805999951 - 2²⁹ = 269129039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 805999892 and 805999901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805999921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22915 + ... + 46228.

It is an arithmetic number, because the mean of its divisors is an integer number (201520188).

Almost surely, 2^805999951 is an apocalyptic number.

805999951 is the 17956-th centered pentagonal number.

805999951 is a deficient number, since it is larger than the sum of its proper divisors (80801).

805999951 is a wasteful number, since it uses less digits than its factorization.

805999951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80800.

The product of its (nonzero) digits is 1312200, while the sum is 55.

The square root of 805999951 is about 28390.1382701811. The cubic root of 805999951 is about 930.6327643491.

The spelling of 805999951 in words is "eight hundred five million, nine hundred ninety-nine thousand, nine hundred fifty-one".