28663700 has 72 divisors (see below), whose sum is σ = 70979832. Its totient is φ = 9953280.

The previous prime is 28663673. The next prime is 28663709. The reversal of 28663700 is 736682.

It can be written as a sum of positive squares in 12 ways, for example, as 1331716 + 27331984 = 1154^2 + 5228^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28663709) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21452 + ... + 22748.

It is an arithmetic number, because the mean of its divisors is an integer number (985831).

Almost surely, 2^28663700 is an apocalyptic number.

28663700 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 28663700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35489916).

28663700 is an abundant number, since it is smaller than the sum of its proper divisors (42316132).

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

28663700 is a wasteful number, since it uses less digits than its factorization.

28663700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1341 (or 1334 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 28663700 is about 5353.8490826694. The cubic root of 28663700 is about 306.0394526715.

The spelling of 28663700 in words is "twenty-eight million, six hundred sixty-three thousand, seven hundred".