28281988 has 24 divisors (see below), whose sum is σ = 56952000. Its totient is φ = 12037728.

The previous prime is 28281971. The next prime is 28281991. The reversal of 28281988 is 88918282.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 783 + ... + 7561.

It is an arithmetic number, because the mean of its divisors is an integer number (2373000).

Almost surely, 2^28281988 is an apocalyptic number.

28281988 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28281988 is an abundant number, since it is smaller than the sum of its proper divisors (28670012).

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

28281988 is a wasteful number, since it uses less digits than its factorization.

28281988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6939 (or 6937 counting only the distinct ones).

The product of its digits is 147456, while the sum is 46.

The square root of 28281988 is about 5318.0812329260. The cubic root of 28281988 is about 304.6748770558.

The spelling of 28281988 in words is "twenty-eight million, two hundred eighty-one thousand, nine hundred eighty-eight".