28299840 has 112 divisors (see below), whose sum is σ = 92171520. Its totient is φ = 7352320.

The previous prime is 28299839. The next prime is 28299841. The reversal of 28299840 is 4899282.

It is an interprime number because it is at equal distance from previous prime (28299839) and next prime (28299841).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28299792 and 28299801.

It is not an unprimeable number, because it can be changed into a prime (28299841) 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, 39001 + ... + 39719.

It is an arithmetic number, because the mean of its divisors is an integer number (822960).

Almost surely, 2^28299840 is an apocalyptic number.

28299840 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 28299840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46085760).

28299840 is an abundant number, since it is smaller than the sum of its proper divisors (63871680).

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

28299840 is a wasteful number, since it uses less digits than its factorization.

28299840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 28299840 is about 5319.7593930553. The cubic root of 28299840 is about 304.7389686360.

The spelling of 28299840 in words is "twenty-eight million, two hundred ninety-nine thousand, eight hundred forty".