28420240 has 40 divisors (see below), whose sum is σ = 66299328. Its totient is φ = 11329920.

The previous prime is 28420237. The next prime is 28420247. The reversal of 28420240 is 4202482.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (28420247) 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, 44725 + ... + 45355.

Almost surely, 2^28420240 is an apocalyptic number.

28420240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28420240 is an abundant number, since it is smaller than the sum of its proper divisors (37879088).

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

28420240 is a wasteful number, since it uses less digits than its factorization.

28420240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1207 (or 1201 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

The square root of 28420240 is about 5331.0636837314. The cubic root of 28420240 is about 305.1705218631.

The spelling of 28420240 in words is "twenty-eight million, four hundred twenty thousand, two hundred forty".