28139560 has 16 divisors (see below), whose sum is σ = 63314100. Its totient is φ = 11255808.

The previous prime is 28139543. The next prime is 28139561. The reversal of 28139560 is 6593182.

It can be written as a sum of positive squares in 2 ways, for example, as 28068804 + 70756 = 5298^2 + 266^2 .

It is not an unprimeable number, because it can be changed into a prime (28139561) 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, 351705 + ... + 351784.

Almost surely, 2^28139560 is an apocalyptic number.

28139560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28139560 is an abundant number, since it is smaller than the sum of its proper divisors (35174540).

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

28139560 is a wasteful number, since it uses less digits than its factorization.

28139560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 703500 (or 703496 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 28139560 is about 5304.6734112479. The cubic root of 28139560 is about 304.1625688654.

The spelling of 28139560 in words is "twenty-eight million, one hundred thirty-nine thousand, five hundred sixty".