28031800 has 24 divisors (see below), whose sum is σ = 65174400. Its totient is φ = 11212640.

The previous prime is 28031771. The next prime is 28031803. The reversal of 28031800 is 813082.

It is a super-2 number, since 2×28031800² = 1571563622480000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28031803) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69880 + ... + 70279.

It is an arithmetic number, because the mean of its divisors is an integer number (2715600).

Almost surely, 2^28031800 is an apocalyptic number.

28031800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28031800 is an abundant number, since it is smaller than the sum of its proper divisors (37142600).

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

28031800 is a wasteful number, since it uses less digits than its factorization.

28031800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140175 (or 140166 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 28031800 is about 5294.5065870202. The cubic root of 28031800 is about 303.7738102782.

Adding to 28031800 its reverse (813082), we get a palindrome (28844882).

The spelling of 28031800 in words is "twenty-eight million, thirty-one thousand, eight hundred".