28786628 has 12 divisors (see below), whose sum is σ = 54251820. Its totient is φ = 13286112.

The previous prime is 28786621. The next prime is 28786643. The reversal of 28786628 is 82668782.

It can be written as a sum of positive squares in 2 ways, for example, as 17909824 + 10876804 = 4232^2 + 3298^2 .

It is a super-2 number, since 2×28786628² = 1657339903220768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28786621) 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, 276743 + ... + 276846.

It is an arithmetic number, because the mean of its divisors is an integer number (4520985).

Almost surely, 2^28786628 is an apocalyptic number.

It is an amenable number.

28786628 is a deficient number, since it is larger than the sum of its proper divisors (25465192).

28786628 is a wasteful number, since it uses less digits than its factorization.

28786628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553606 (or 553604 counting only the distinct ones).

The product of its digits is 516096, while the sum is 47.

The square root of 28786628 is about 5365.3171388092. The cubic root of 28786628 is about 306.4763253830.

The spelling of 28786628 in words is "twenty-eight million, seven hundred eighty-six thousand, six hundred twenty-eight".