28756628 has 6 divisors (see below), whose sum is σ = 50324106. Its totient is φ = 14378312.

The previous prime is 28756613. The next prime is 28756631. The reversal of 28756628 is 82665782.

It can be written as a sum of positive squares in only one way, i.e., 26234884 + 2521744 = 5122^2 + 1588^2 .

It is a super-3 number, since 3×28756628³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 3594575 + ... + 3594582.

It is an arithmetic number, because the mean of its divisors is an integer number (8387351).

Almost surely, 2^28756628 is an apocalyptic number.

It is an amenable number.

28756628 is a deficient number, since it is larger than the sum of its proper divisors (21567478).

28756628 is a wasteful number, since it uses less digits than its factorization.

28756628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7189161 (or 7189159 counting only the distinct ones).

The product of its digits is 322560, while the sum is 44.

The square root of 28756628 is about 5362.5206759508. The cubic root of 28756628 is about 306.3698235545.

The spelling of 28756628 in words is "twenty-eight million, seven hundred fifty-six thousand, six hundred twenty-eight".