28681257 has 16 divisors (see below), whose sum is σ = 42428160. Its totient is φ = 17086800.

The previous prime is 28681217. The next prime is 28681283. The reversal of 28681257 is 75218682.

It is not a de Polignac number, because 28681257 - 2⁸ = 28681001 is a prime.

It is a super-2 number, since 2×28681257² = 1645229006200098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28681217) 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, 5419 + ... + 9312.

It is an arithmetic number, because the mean of its divisors is an integer number (2651760).

Almost surely, 2^28681257 is an apocalyptic number.

It is an amenable number.

28681257 is a deficient number, since it is larger than the sum of its proper divisors (13746903).

28681257 is a wasteful number, since it uses less digits than its factorization.

28681257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14804.

The product of its digits is 53760, while the sum is 39.

The square root of 28681257 is about 5355.4884931255. The cubic root of 28681257 is about 306.1019246948.

The spelling of 28681257 in words is "twenty-eight million, six hundred eighty-one thousand, two hundred fifty-seven".