28011840 has 56 divisors (see below), whose sum is σ = 88940640. Its totient is φ = 7469568.

The previous prime is 28011839. The next prime is 28011847. The reversal of 28011840 is 4811082.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 28011840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28011847) 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, 13630 + ... + 15549.

Almost surely, 2^28011840 is an apocalyptic number.

28011840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28011840 is an abundant number, since it is smaller than the sum of its proper divisors (60928800).

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

28011840 is a wasteful number, since it uses less digits than its factorization.

28011840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29199 (or 29189 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 28011840 is about 5292.6212787238. The cubic root of 28011840 is about 303.7016926006.

The spelling of 28011840 in words is "twenty-eight million, eleven thousand, eight hundred forty".