7128985 has 4 divisors (see below), whose sum is σ = 8554788. Its totient is φ = 5703184.

The previous prime is 7128973. The next prime is 7128991. The reversal of 7128985 is 5898217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5898217 = 13 ⋅453709.

It can be written as a sum of positive squares in 2 ways, for example, as 913936 + 6215049 = 956^2 + 2493^2 .

It is a cyclic number.

It is not a de Polignac number, because 7128985 - 2²¹ = 5031833 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a zygodrome in base 7.

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, 712894 + ... + 712903.

It is an arithmetic number, because the mean of its divisors is an integer number (2138697).

Almost surely, 2^7128985 is an apocalyptic number.

It is an amenable number.

7128985 is a deficient number, since it is larger than the sum of its proper divisors (1425803).

7128985 is a wasteful number, since it uses less digits than its factorization.

7128985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1425802.

The product of its digits is 40320, while the sum is 40.

The square root of 7128985 is about 2670.0159175555. The cubic root of 7128985 is about 192.4609242100.

The spelling of 7128985 in words is "seven million, one hundred twenty-eight thousand, nine hundred eighty-five".