7878545 has 4 divisors (see below), whose sum is σ = 9454260. Its totient is φ = 6302832.

The previous prime is 7878527. The next prime is 7878551. The reversal of 7878545 is 5458787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5458787 = 283 ⋅19289.

It can be written as a sum of positive squares in 2 ways, for example, as 3182656 + 4695889 = 1784^2 + 2167^2 .

It is a cyclic number.

It is not a de Polignac number, because 7878545 - 2⁸ = 7878289 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 7878496 and 7878505.

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, 787850 + ... + 787859.

It is an arithmetic number, because the mean of its divisors is an integer number (2363565).

Almost surely, 2^7878545 is an apocalyptic number.

It is an amenable number.

7878545 is a deficient number, since it is larger than the sum of its proper divisors (1575715).

7878545 is a wasteful number, since it uses less digits than its factorization.

7878545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575714.

The product of its digits is 313600, while the sum is 44.

The square root of 7878545 is about 2806.8745964150. The cubic root of 7878545 is about 198.9827093720.

The spelling of 7878545 in words is "seven million, eight hundred seventy-eight thousand, five hundred forty-five".