28431288 has 24 divisors (see below), whose sum is σ = 77001600. Its totient is φ = 9477072.

The previous prime is 28431269. The next prime is 28431313. The reversal of 28431288 is 88213482.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 197368 + ... + 197511.

It is an arithmetic number, because the mean of its divisors is an integer number (3208400).

Almost surely, 2^28431288 is an apocalyptic number.

It is an amenable number.

28431288 is an abundant number, since it is smaller than the sum of its proper divisors (48570312).

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

28431288 is a wasteful number, since it uses less digits than its factorization.

28431288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394891 (or 394884 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 28431288 is about 5332.0997740102. The cubic root of 28431288 is about 305.2100604354.

The spelling of 28431288 in words is "twenty-eight million, four hundred thirty-one thousand, two hundred eighty-eight".