28724740 has 48 divisors (see below), whose sum is σ = 66951360. Its totient is φ = 10263680.

The previous prime is 28724737. The next prime is 28724749. The reversal of 28724740 is 4742782.

It is a super-2 number, since 2×28724740² = 1650221376135200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28724696 and 28724705.

It is not an unprimeable number, because it can be changed into a prime (28724749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11874 + ... + 14086.

It is an arithmetic number, because the mean of its divisors is an integer number (1394820).

Almost surely, 2^28724740 is an apocalyptic number.

28724740 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 28724740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33475680).

28724740 is an abundant number, since it is smaller than the sum of its proper divisors (38226620).

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

28724740 is a wasteful number, since it uses less digits than its factorization.

28724740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2292 (or 2290 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 34.

The square root of 28724740 is about 5359.5466226165. The cubic root of 28724740 is about 306.2565379695.

The spelling of 28724740 in words is "twenty-eight million, seven hundred twenty-four thousand, seven hundred forty".