28131857 has 8 divisors (see below), whose sum is σ = 30528960. Its totient is φ = 25768080.

The previous prime is 28131853. The next prime is 28131871. The reversal of 28131857 is 75813182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28131857 - 2² = 28131853 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28131853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6557 + ... + 9962.

It is an arithmetic number, because the mean of its divisors is an integer number (3816120).

Almost surely, 2^28131857 is an apocalyptic number.

It is an amenable number.

28131857 is a deficient number, since it is larger than the sum of its proper divisors (2397103).

28131857 is a wasteful number, since it uses less digits than its factorization.

28131857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16663.

The product of its digits is 13440, while the sum is 35.

The square root of 28131857 is about 5303.9473036598. The cubic root of 28131857 is about 304.1348122351.

The spelling of 28131857 in words is "twenty-eight million, one hundred thirty-one thousand, eight hundred fifty-seven".