865138805 has 4 divisors (see below), whose sum is σ = 1038166572. Its totient is φ = 692111040.

The previous prime is 865138753. The next prime is 865138819. The reversal of 865138805 is 508831568.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 189502756 + 675636049 = 13766^2 + 25993^2 .

It is not a de Polignac number, because 865138805 - 2²² = 860944501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86513876 + ... + 86513885.

It is an arithmetic number, because the mean of its divisors is an integer number (259541643).

Almost surely, 2^865138805 is an apocalyptic number.

It is an amenable number.

865138805 is a deficient number, since it is larger than the sum of its proper divisors (173027767).

865138805 is a wasteful number, since it uses less digits than its factorization.

865138805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173027766.

The product of its (nonzero) digits is 230400, while the sum is 44.

The square root of 865138805 is about 29413.2420008404. The cubic root of 865138805 is about 952.8589058565.

The spelling of 865138805 in words is "eight hundred sixty-five million, one hundred thirty-eight thousand, eight hundred five".