28220700 has 72 divisors (see below), whose sum is σ = 85966720. Its totient is φ = 7128000.

The previous prime is 28220671. The next prime is 28220711. The reversal of 28220700 is 702282.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3225 + ... + 8175.

Almost surely, 2^28220700 is an apocalyptic number.

28220700 is a gapful number since it is divisible by the number (20) 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 28220700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42983360).

28220700 is an abundant number, since it is smaller than the sum of its proper divisors (57746020).

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

28220700 is a wasteful number, since it uses less digits than its factorization.

28220700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4987 (or 4980 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 28220700 is about 5312.3158791623. The cubic root of 28220700 is about 304.4546377242.

Adding to 28220700 its reverse (702282), we get a palindrome (28922982).

It can be divided in two parts, 28220 and 700, that added together give a triangular number (28920 = T₂₄₀).

The spelling of 28220700 in words is "twenty-eight million, two hundred twenty thousand, seven hundred".