28128713 has 4 divisors (see below), whose sum is σ = 28343568. Its totient is φ = 27913860.

The previous prime is 28128707. The next prime is 28128719. The reversal of 28128713 is 31782182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (28128707) and next prime (28128719).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28128713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28128713.

It is not an unprimeable number, because it can be changed into a prime (28128719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107231 + ... + 107492.

It is an arithmetic number, because the mean of its divisors is an integer number (7085892).

Almost surely, 2^28128713 is an apocalyptic number.

It is an amenable number.

28128713 is a deficient number, since it is larger than the sum of its proper divisors (214855).

28128713 is a wasteful number, since it uses less digits than its factorization.

28128713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214854.

The product of its digits is 5376, while the sum is 32.

The square root of 28128713 is about 5303.6509123433. The cubic root of 28128713 is about 304.1234818363.

The spelling of 28128713 in words is "twenty-eight million, one hundred twenty-eight thousand, seven hundred thirteen".