28381660 has 12 divisors (see below), whose sum is σ = 59601528. Its totient is φ = 11352656.

The previous prime is 28381651. The next prime is 28381663. The reversal of 28381660 is 6618382.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28381663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 709522 + ... + 709561.

It is an arithmetic number, because the mean of its divisors is an integer number (4966794).

Almost surely, 2^28381660 is an apocalyptic number.

28381660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28381660 is an abundant number, since it is smaller than the sum of its proper divisors (31219868).

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

28381660 is a wasteful number, since it uses less digits than its factorization.

28381660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419092 (or 1419090 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28381660 is about 5327.4440400627. Note that the first 3 decimals coincide. The cubic root of 28381660 is about 305.0323713738.

The spelling of 28381660 in words is "twenty-eight million, three hundred eighty-one thousand, six hundred sixty".