28920240 has 100 divisors (see below), whose sum is σ = 100466784. Its totient is φ = 7710336.

The previous prime is 28920233. The next prime is 28920251. The reversal of 28920240 is 4202982.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4249 + ... + 8711.

Almost surely, 2^28920240 is an apocalyptic number.

28920240 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 28920240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50233392).

28920240 is an abundant number, since it is smaller than the sum of its proper divisors (71546544).

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

28920240 is a wasteful number, since it uses less digits than its factorization.

28920240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4488 (or 4473 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 28920240 is about 5377.7541780933. The cubic root of 28920240 is about 306.9497595923.

The spelling of 28920240 in words is "twenty-eight million, nine hundred twenty thousand, two hundred forty".