7858945 has 4 divisors (see below), whose sum is σ = 9430740. Its totient is φ = 6287152.

The previous prime is 7858937. The next prime is 7858957. The reversal of 7858945 is 5498587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5498587 = 23 ⋅239069.

It can be written as a sum of positive squares in 2 ways, for example, as 804609 + 7054336 = 897^2 + 2656^2 .

It is a cyclic number.

It is not a de Polignac number, because 7858945 - 2³ = 7858937 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 = 7858895 and 7858904.

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, 785890 + ... + 785899.

It is an arithmetic number, because the mean of its divisors is an integer number (2357685).

Almost surely, 2^7858945 is an apocalyptic number.

It is an amenable number.

7858945 is a deficient number, since it is larger than the sum of its proper divisors (1571795).

7858945 is a wasteful number, since it uses less digits than its factorization.

7858945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571794.

The product of its digits is 403200, while the sum is 46.

The square root of 7858945 is about 2803.3809944422. The cubic root of 7858945 is about 198.8175646771.

It can be divided in two parts, 785 and 8945, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 7858945 in words is "seven million, eight hundred fifty-eight thousand, nine hundred forty-five".