28917788 has 12 divisors (see below), whose sum is σ = 51464280. Its totient is φ = 14213712.

The previous prime is 28917767. The next prime is 28917797. The reversal of 28917788 is 88771982.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61031 + ... + 61502.

It is an arithmetic number, because the mean of its divisors is an integer number (4288690).

Almost surely, 2^28917788 is an apocalyptic number.

It is an amenable number.

28917788 is a deficient number, since it is larger than the sum of its proper divisors (22546492).

28917788 is a wasteful number, since it uses less digits than its factorization.

28917788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122596 (or 122594 counting only the distinct ones).

The product of its digits is 451584, while the sum is 50.

The square root of 28917788 is about 5377.5261970538. The cubic root of 28917788 is about 306.9410844443.

The spelling of 28917788 in words is "twenty-eight million, nine hundred seventeen thousand, seven hundred eighty-eight".