869851 has 4 divisors (see below), whose sum is σ = 874552. Its totient is φ = 865152.

The previous prime is 869849. The next prime is 869863. The reversal of 869851 is 158968.

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

It is a cyclic number.

It is not a de Polignac number, because 869851 - 2¹ = 869849 is a prime.

It is a Duffinian number.

869851 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 869851.

It is not an unprimeable number, because it can be changed into a prime (869251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2061 + ... + 2446.

It is an arithmetic number, because the mean of its divisors is an integer number (218638).

2⁸⁶⁹⁸⁵¹ is an apocalyptic number.

869851 is a deficient number, since it is larger than the sum of its proper divisors (4701).

869851 is a wasteful number, since it uses less digits than its factorization.

869851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4700.

The product of its digits is 17280, while the sum is 37.

The square root of 869851 is about 932.6580295049. The cubic root of 869851 is about 95.4585769204.

The spelling of 869851 in words is "eight hundred sixty-nine thousand, eight hundred fifty-one".