28139361 has 16 divisors (see below), whose sum is σ = 40146240. Its totient is φ = 17478720.

The previous prime is 28139357. The next prime is 28139381. The reversal of 28139361 is 16393182.

It is not a de Polignac number, because 28139361 - 2² = 28139357 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28139311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 570 + ... + 7523.

It is an arithmetic number, because the mean of its divisors is an integer number (2509140).

Almost surely, 2^28139361 is an apocalyptic number.

It is an amenable number.

28139361 is a deficient number, since it is larger than the sum of its proper divisors (12006879).

28139361 is a wasteful number, since it uses less digits than its factorization.

28139361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8176.

The product of its digits is 7776, while the sum is 33.

The square root of 28139361 is about 5304.6546541693. The cubic root of 28139361 is about 304.1618518618.

The spelling of 28139361 in words is "twenty-eight million, one hundred thirty-nine thousand, three hundred sixty-one".