28137708 has 72 divisors (see below), whose sum is σ = 77342720. Its totient is φ = 8592480.

The previous prime is 28137679. The next prime is 28137719. The reversal of 28137708 is 80773182.

28137708 is a `hidden beast` number, since 281 + 377 + 0 + 8 = 666.

It is a super-2 number, since 2×28137708² = 1583461222986528, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20541 + ... + 21867.

Almost surely, 2^28137708 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 28137708, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38671360).

28137708 is an abundant number, since it is smaller than the sum of its proper divisors (49205012).

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

28137708 is a wasteful number, since it uses less digits than its factorization.

28137708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 28137708 is about 5304.4988453199. The cubic root of 28137708 is about 304.1558959177.

The spelling of 28137708 in words is "twenty-eight million, one hundred thirty-seven thousand, seven hundred eight".