7856545 has 4 divisors (see below), whose sum is σ = 9427860. Its totient is φ = 6285232.

The previous prime is 7856507. The next prime is 7856579. The reversal of 7856545 is 5456587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5456587 = 223 ⋅24469.

It can be written as a sum of positive squares in 2 ways, for example, as 2211169 + 5645376 = 1487^2 + 2376^2 .

It is a cyclic number.

It is not a de Polignac number, because 7856545 - 2⁷ = 7856417 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 = 7856498 and 7856507.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785650 + ... + 785659.

It is an arithmetic number, because the mean of its divisors is an integer number (2356965).

Almost surely, 2^7856545 is an apocalyptic number.

It is an amenable number.

7856545 is a deficient number, since it is larger than the sum of its proper divisors (1571315).

7856545 is a wasteful number, since it uses less digits than its factorization.

7856545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571314.

The product of its digits is 168000, while the sum is 40.

The square root of 7856545 is about 2802.9529072034. The cubic root of 7856545 is about 198.7973240156.

The spelling of 7856545 in words is "seven million, eight hundred fifty-six thousand, five hundred forty-five".