816851 has 8 divisors (see below), whose sum is σ = 949344. Its totient is φ = 688320.

The previous prime is 816847. The next prime is 816857. The reversal of 816851 is 158618.

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 816851 - 2² = 816847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 530 + ... + 1383.

It is an arithmetic number, because the mean of its divisors is an integer number (118668).

2⁸¹⁶⁸⁵¹ is an apocalyptic number.

816851 is a deficient number, since it is larger than the sum of its proper divisors (132493).

816851 is a wasteful number, since it uses less digits than its factorization.

816851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981.

The product of its digits is 1920, while the sum is 29.

The square root of 816851 is about 903.7980969221. The cubic root of 816851 is about 93.4790481808.

It can be divided in two parts, 81 and 6851, that multiplied together give a triangular number (554931 = T₁₀₅₃).

The spelling of 816851 in words is "eight hundred sixteen thousand, eight hundred fifty-one".