28147840 has 128 divisors (see below), whose sum is σ = 78923520. Its totient is φ = 9400320.

The previous prime is 28147831. The next prime is 28147849. The reversal of 28147840 is 4874182.

It is an interprime number because it is at equal distance from previous prime (28147831) and next prime (28147849).

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 28147796 and 28147805.

It is not an unprimeable number, because it can be changed into a prime (28147849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 273229 + ... + 273331.

It is an arithmetic number, because the mean of its divisors is an integer number (616590).

Almost surely, 2^28147840 is an apocalyptic number.

28147840 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 28147840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39461760).

28147840 is an abundant number, since it is smaller than the sum of its proper divisors (50775680).

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

28147840 is a wasteful number, since it uses less digits than its factorization.

28147840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 28147840 is about 5305.4537977444. The cubic root of 28147840 is about 304.1923989823.

The spelling of 28147840 in words is "twenty-eight million, one hundred forty-seven thousand, eight hundred forty".