28261440 has 112 divisors (see below), whose sum is σ = 99730560. Its totient is φ = 7534080.

The previous prime is 28261433. The next prime is 28261447. The reversal of 28261440 is 4416282.

28261440 is a `hidden beast` number, since 2 + 8 + 2 + 614 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (28261433) and next prime (28261447).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (28261447) 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, 7005 + ... + 10275.

Almost surely, 2^28261440 is an apocalyptic number.

28261440 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 28261440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49865280).

28261440 is an abundant number, since it is smaller than the sum of its proper divisors (71469120).

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

28261440 is a wasteful number, since it uses less digits than its factorization.

28261440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3297 (or 3281 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28261440 is about 5316.1489821110. The cubic root of 28261440 is about 304.6010730014.

The spelling of 28261440 in words is "twenty-eight million, two hundred sixty-one thousand, four hundred forty".