28431880 has 32 divisors (see below), whose sum is σ = 64131840. Its totient is φ = 11344320.

The previous prime is 28431869. The next prime is 28431881. The reversal of 28431880 is 8813482.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28431881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23695 + ... + 24865.

It is an arithmetic number, because the mean of its divisors is an integer number (2004120).

Almost surely, 2^28431880 is an apocalyptic number.

28431880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28431880 is an abundant number, since it is smaller than the sum of its proper divisors (35699960).

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

28431880 is a wasteful number, since it uses less digits than its factorization.

28431880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1789 (or 1785 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 28431880 is about 5332.1552865610. The cubic root of 28431880 is about 305.2121787953.

The spelling of 28431880 in words is "twenty-eight million, four hundred thirty-one thousand, eight hundred eighty".