8139805 has 8 divisors (see below), whose sum is σ = 9811800. Its totient is φ = 6482496.

The previous prime is 8139797. The next prime is 8139829. The reversal of 8139805 is 5089318.

It can be written as a sum of positive squares in 4 ways, for example, as 1138489 + 7001316 = 1067^2 + 2646^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8139805 - 2³ = 8139797 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2410 + ... + 4699.

It is an arithmetic number, because the mean of its divisors is an integer number (1226475).

Almost surely, 2^8139805 is an apocalyptic number.

It is an amenable number.

8139805 is a deficient number, since it is larger than the sum of its proper divisors (1671995).

8139805 is a wasteful number, since it uses less digits than its factorization.

8139805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7343.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 8139805 is about 2853.0343496004. The cubic root of 8139805 is about 201.1583201873.

The spelling of 8139805 in words is "eight million, one hundred thirty-nine thousand, eight hundred five".