28399760 has 20 divisors (see below), whose sum is σ = 66029628. Its totient is φ = 11359872.

The previous prime is 28399747. The next prime is 28399769. The reversal of 28399760 is 6799382.

It can be written as a sum of positive squares in 2 ways, for example, as 5513104 + 22886656 = 2348^2 + 4784^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28399769) 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, 177419 + ... + 177578.

Almost surely, 2^28399760 is an apocalyptic number.

28399760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28399760 is an abundant number, since it is smaller than the sum of its proper divisors (37629868).

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

28399760 is a wasteful number, since it uses less digits than its factorization.

28399760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355010 (or 355004 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 28399760 is about 5329.1425201434. The cubic root of 28399760 is about 305.0972009465.

The spelling of 28399760 in words is "twenty-eight million, three hundred ninety-nine thousand, seven hundred sixty".