7878645 has 12 divisors (see below), whose sum is σ = 13656396. Its totient is φ = 4201920.

The previous prime is 7878643. The next prime is 7878649. The reversal of 7878645 is 5468787.

It can be written as a sum of positive squares in 2 ways, for example, as 5574321 + 2304324 = 2361^2 + 1518^2 .

It is not a de Polignac number, because 7878645 - 2¹ = 7878643 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 175081 = 7878645 / (7 + 8 + 7 + 8 + 6 + 4 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 7878645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7878641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87496 + ... + 87585.

It is an arithmetic number, because the mean of its divisors is an integer number (1138033).

Almost surely, 2^7878645 is an apocalyptic number.

It is an amenable number.

7878645 is a deficient number, since it is larger than the sum of its proper divisors (5777751).

7878645 is a wasteful number, since it uses less digits than its factorization.

7878645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175092 (or 175089 counting only the distinct ones).

The product of its digits is 376320, while the sum is 45.

The square root of 7878645 is about 2806.8924097656. The cubic root of 7878645 is about 198.9835512443.

The spelling of 7878645 in words is "seven million, eight hundred seventy-eight thousand, six hundred forty-five".