28861440 has 88 divisors (see below), whose sum is σ = 92360640. Its totient is φ = 7692288.

The previous prime is 28861439. The next prime is 28861447. The reversal of 28861440 is 4416882.

It is not an unprimeable number, because it can be changed into a prime (28861447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14421 + ... + 16299.

Almost surely, 2^28861440 is an apocalyptic number.

28861440 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 28861440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46180320).

28861440 is an abundant number, since it is smaller than the sum of its proper divisors (63499200).

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

28861440 is a wasteful number, since it uses less digits than its factorization.

28861440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1907 (or 1889 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 28861440 is about 5372.2844302959. The cubic root of 28861440 is about 306.7415905990.

The spelling of 28861440 in words is "twenty-eight million, eight hundred sixty-one thousand, four hundred forty".