28405740 has 96 divisors (see below), whose sum is σ = 87607296. Its totient is φ = 6819840.

The previous prime is 28405739. The next prime is 28405781. The reversal of 28405740 is 4750482.

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 = 28405698 and 28405707.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 127269 + ... + 127491.

It is an arithmetic number, because the mean of its divisors is an integer number (912576).

Almost surely, 2^28405740 is an apocalyptic number.

28405740 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 28405740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43803648).

28405740 is an abundant number, since it is smaller than the sum of its proper divisors (59201556).

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

28405740 is a wasteful number, since it uses less digits than its factorization.

28405740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 30.

The square root of 28405740 is about 5329.7035564842. The cubic root of 28405740 is about 305.1186137239.

The spelling of 28405740 in words is "twenty-eight million, four hundred five thousand, seven hundred forty".