28431816 has 64 divisors (see below), whose sum is σ = 82252800. Its totient is φ = 8021568.

The previous prime is 28431791. The next prime is 28431829. The reversal of 28431816 is 61813482.

It is a super-2 number, since 2×28431816² = 1616736322115712, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12925 + ... + 14963.

It is an arithmetic number, because the mean of its divisors is an integer number (1285200).

Almost surely, 2^28431816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28431816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41126400).

28431816 is an abundant number, since it is smaller than the sum of its proper divisors (53820984).

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

28431816 is a wasteful number, since it uses less digits than its factorization.

28431816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2138 (or 2134 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 28431816 is about 5332.1492852320. The cubic root of 28431816 is about 305.2119497848.

The spelling of 28431816 in words is "twenty-eight million, four hundred thirty-one thousand, eight hundred sixteen".