7871845 has 4 divisors (see below), whose sum is σ = 9446220. Its totient is φ = 6297472.

The previous prime is 7871837. The next prime is 7871863. The reversal of 7871845 is 5481787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5481787 = 1109 ⋅4943.

It can be written as a sum of positive squares in 2 ways, for example, as 2405601 + 5466244 = 1551^2 + 2338^2 .

It is a cyclic number.

It is not a de Polignac number, because 7871845 - 2³ = 7871837 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 7871798 and 7871807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 787180 + ... + 787189.

It is an arithmetic number, because the mean of its divisors is an integer number (2361555).

Almost surely, 2^7871845 is an apocalyptic number.

It is an amenable number.

7871845 is a deficient number, since it is larger than the sum of its proper divisors (1574375).

7871845 is a wasteful number, since it uses less digits than its factorization.

7871845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574374.

The product of its digits is 62720, while the sum is 40.

The square root of 7871845 is about 2805.6808442872. The cubic root of 7871845 is about 198.9262876914.

The spelling of 7871845 in words is "seven million, eight hundred seventy-one thousand, eight hundred forty-five".