7851 has 4 divisors (see below), whose sum is σ = 10472. Its totient is φ = 5232.

The previous prime is 7841. The next prime is 7853. The reversal of 7851 is 1587.

It is a happy number.

7851 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 7851 - 2⁷ = 7723 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7853) 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, 1306 + ... + 1311.

It is an arithmetic number, because the mean of its divisors is an integer number (2618).

2⁷⁸⁵¹ is an apocalyptic number.

7851 is a deficient number, since it is larger than the sum of its proper divisors (2621).

7851 is a wasteful number, since it uses less digits than its factorization.

7851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2620.

The product of its digits is 280, while the sum is 21.

The square root of 7851 is about 88.6058688801. The cubic root of 7851 is about 19.8750543885.

It can be divided in two parts, 7 and 851, that added together give a palindrome (858).

The spelling of 7851 in words is "seven thousand, eight hundred fifty-one".