28131867 has 12 divisors (see below), whose sum is σ = 42140280. Its totient is φ = 18754416.

The previous prime is 28131853. The next prime is 28131871. The reversal of 28131867 is 76813182.

28131867 is a `hidden beast` number, since 281 + 318 + 67 = 666.

It is not a de Polignac number, because 28131867 - 2⁸ = 28131611 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28131767) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57642 + ... + 58127.

It is an arithmetic number, because the mean of its divisors is an integer number (3511690).

Almost surely, 2^28131867 is an apocalyptic number.

28131867 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28131867 is a deficient number, since it is larger than the sum of its proper divisors (14008413).

28131867 is an equidigital number, since it uses as much as digits as its factorization.

28131867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115784 (or 115772 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 28131867 is about 5303.9482463538. The cubic root of 28131867 is about 304.1348482719.

The spelling of 28131867 in words is "twenty-eight million, one hundred thirty-one thousand, eight hundred sixty-seven".