28287140 has 48 divisors (see below), whose sum is σ = 68621952. Its totient is φ = 9593856.

The previous prime is 28287139. The next prime is 28287169. The reversal of 28287140 is 4178282.

It is a junction number, because it is equal to n+sod(n) for n = 28287097 and 28287106.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12539 + ... + 14621.

It is an arithmetic number, because the mean of its divisors is an integer number (1429624).

Almost surely, 2^28287140 is an apocalyptic number.

28287140 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 28287140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34310976).

28287140 is an abundant number, since it is smaller than the sum of its proper divisors (40334812).

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

28287140 is a wasteful number, since it uses less digits than its factorization.

28287140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2196 (or 2194 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 28287140 is about 5318.5655960983. The cubic root of 28287140 is about 304.6933763408.

The spelling of 28287140 in words is "twenty-eight million, two hundred eighty-seven thousand, one hundred forty".