28306740 has 144 divisors (see below), whose sum is σ = 99743616. Its totient is φ = 5871360.

The previous prime is 28306723. The next prime is 28306741. The reversal of 28306740 is 4760382.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28306698 and 28306707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28306741) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50542 + ... + 51098.

It is an arithmetic number, because the mean of its divisors is an integer number (692664).

Almost surely, 2^28306740 is an apocalyptic number.

28306740 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 28306740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49871808).

28306740 is an abundant number, since it is smaller than the sum of its proper divisors (71436876).

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

28306740 is a wasteful number, since it uses less digits than its factorization.

28306740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 585 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 28306740 is about 5320.4078791010. The cubic root of 28306740 is about 304.7637335347.

The spelling of 28306740 in words is "twenty-eight million, three hundred six thousand, seven hundred forty".