28890988 has 36 divisors (see below), whose sum is σ = 59166912. Its totient is φ = 12307680.

The previous prime is 28890959. The next prime is 28890997. The reversal of 28890988 is 88909882.

It is a super-2 number, since 2×28890988² = 1669378375232288, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43378 + ... + 44038.

Almost surely, 2^28890988 is an apocalyptic number.

28890988 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28890988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29583456).

28890988 is an abundant number, since it is smaller than the sum of its proper divisors (30275924).

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

28890988 is a wasteful number, since it uses less digits than its factorization.

28890988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 52.

The square root of 28890988 is about 5375.0337673358. The cubic root of 28890988 is about 306.8462343637.

The spelling of 28890988 in words is "twenty-eight million, eight hundred ninety thousand, nine hundred eighty-eight".