816856205 has 16 divisors (see below), whose sum is σ = 1132242624. Its totient is φ = 559130880.

The previous prime is 816856181. The next prime is 816856223. The reversal of 816856205 is 502658618.

It is a de Polignac number, because none of the positive numbers 2^k-816856205 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 435887 + ... + 437756.

It is an arithmetic number, because the mean of its divisors is an integer number (70765164).

Almost surely, 2^816856205 is an apocalyptic number.

816856205 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

816856205 is a deficient number, since it is larger than the sum of its proper divisors (315386419).

816856205 is a wasteful number, since it uses less digits than its factorization.

816856205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873676.

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 816856205 is about 28580.6963701027. The cubic root of 816856205 is about 934.7924673084.

The spelling of 816856205 in words is "eight hundred sixteen million, eight hundred fifty-six thousand, two hundred five".