28138340 has 24 divisors (see below), whose sum is σ = 60466560. Its totient is φ = 10993248.

The previous prime is 28138333. The next prime is 28138367. The reversal of 28138340 is 4383182.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15500 + ... + 17219.

It is an arithmetic number, because the mean of its divisors is an integer number (2519440).

Almost surely, 2^28138340 is an apocalyptic number.

28138340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28138340 is an abundant number, since it is smaller than the sum of its proper divisors (32328220).

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

28138340 is a wasteful number, since it uses less digits than its factorization.

28138340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32771 (or 32769 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 28138340 is about 5304.5584170598. The cubic root of 28138340 is about 304.1581731120.

The spelling of 28138340 in words is "twenty-eight million, one hundred thirty-eight thousand, three hundred forty".