28531500 has 96 divisors (see below), whose sum is σ = 86800896. Its totient is φ = 7268800.

The previous prime is 28531487. The next prime is 28531507. The reversal of 28531500 is 513582.

28531500 = 1885² + 1886² + ... + 1892².

It is not an unprimeable number, because it can be changed into a prime (28531507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34087 + ... + 34913.

It is an arithmetic number, because the mean of its divisors is an integer number (904176).

Almost surely, 2^28531500 is an apocalyptic number.

28531500 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 28531500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43400448).

28531500 is an abundant number, since it is smaller than the sum of its proper divisors (58269396).

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

28531500 is a wasteful number, since it uses less digits than its factorization.

28531500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 860 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 28531500 is about 5341.4885565730. The cubic root of 28531500 is about 305.5682321034.

The spelling of 28531500 in words is "twenty-eight million, five hundred thirty-one thousand, five hundred".