805138851 has 64 divisors (see below), whose sum is σ = 1328578560. Its totient is φ = 427680000.

The previous prime is 805138843. The next prime is 805138877. The reversal of 805138851 is 158831508.

It is not a de Polignac number, because 805138851 - 2³ = 805138843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (805138891) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 446151 + ... + 447951.

It is an arithmetic number, because the mean of its divisors is an integer number (20759040).

Almost surely, 2^805138851 is an apocalyptic number.

805138851 is a deficient number, since it is larger than the sum of its proper divisors (523439709).

805138851 is a wasteful number, since it uses less digits than its factorization.

805138851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1888.

The product of its (nonzero) digits is 38400, while the sum is 39.

The square root of 805138851 is about 28374.9687400709. The cubic root of 805138851 is about 930.3012285859.

It can be divided in two parts, 805 and 138851, that added together give a triangular number (139656 = T₅₂₈).

The spelling of 805138851 in words is "eight hundred five million, one hundred thirty-eight thousand, eight hundred fifty-one".