28137564 has 144 divisors (see below), whose sum is σ = 91610400. Its totient is φ = 7402752.

The previous prime is 28137563. The next prime is 28137589. The reversal of 28137564 is 46573182.

28137564 is a `hidden beast` number, since 281 + 375 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28137563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 68592 + ... + 69000.

Almost surely, 2^28137564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28137564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45805200).

28137564 is an abundant number, since it is smaller than the sum of its proper divisors (63472836).

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

28137564 is a wasteful number, since it uses less digits than its factorization.

28137564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449 (or 434 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 28137564 is about 5304.4852719185. The cubic root of 28137564 is about 304.1553770585.

The spelling of 28137564 in words is "twenty-eight million, one hundred thirty-seven thousand, five hundred sixty-four".