28678788 has 18 divisors (see below), whose sum is σ = 72493694. Its totient is φ = 9559584.

The previous prime is 28678787. The next prime is 28678801. The reversal of 28678788 is 88787682.

It can be written as a sum of positive squares in only one way, i.e., 27060804 + 1617984 = 5202^2 + 1272^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×28678788² = 1644945762297888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28678781) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 398281 + ... + 398352.

Almost surely, 2^28678788 is an apocalyptic number.

It is an amenable number.

28678788 is an abundant number, since it is smaller than the sum of its proper divisors (43814906).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28678788 is a wasteful number, since it uses less digits than its factorization.

28678788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796643 (or 796638 counting only the distinct ones).

The product of its digits is 2408448, while the sum is 54.

The square root of 28678788 is about 5355.2579769793. The cubic root of 28678788 is about 306.0931409405.

The spelling of 28678788 in words is "twenty-eight million, six hundred seventy-eight thousand, seven hundred eighty-eight".