7878861 has 6 divisors (see below), whose sum is σ = 11380590. Its totient is φ = 5252568.

The previous prime is 7878859. The next prime is 7878869. The reversal of 7878861 is 1688787.

It can be written as a sum of positive squares in only one way, i.e., 4076361 + 3802500 = 2019^2 + 1950^2 .

It is not a de Polignac number, because 7878861 - 2¹ = 7878859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7878869) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 437706 + ... + 437723.

It is an arithmetic number, because the mean of its divisors is an integer number (1896765).

Almost surely, 2^7878861 is an apocalyptic number.

It is an amenable number.

7878861 is a deficient number, since it is larger than the sum of its proper divisors (3501729).

7878861 is a wasteful number, since it uses less digits than its factorization.

7878861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875435 (or 875432 counting only the distinct ones).

The product of its digits is 150528, while the sum is 45.

The square root of 7878861 is about 2806.9308862172. The cubic root of 7878861 is about 198.9853696642.

The spelling of 7878861 in words is "seven million, eight hundred seventy-eight thousand, eight hundred sixty-one".