28726857 has 12 divisors (see below), whose sum is σ = 41629380. Its totient is φ = 19088928.

The previous prime is 28726847. The next prime is 28726861. The reversal of 28726857 is 75862782.

It can be written as a sum of positive squares in 2 ways, for example, as 4016016 + 24710841 = 2004^2 + 4971^2 .

It is not a de Polignac number, because 28726857 - 2⁸ = 28726601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28726807) 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 11 ways as a sum of consecutive naturals, for example, 2182 + ... + 7887.

It is an arithmetic number, because the mean of its divisors is an integer number (3469115).

Almost surely, 2^28726857 is an apocalyptic number.

It is an amenable number.

28726857 is a deficient number, since it is larger than the sum of its proper divisors (12902523).

28726857 is a wasteful number, since it uses less digits than its factorization.

28726857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10392 (or 10389 counting only the distinct ones).

The product of its digits is 376320, while the sum is 45.

The square root of 28726857 is about 5359.7441170265. The cubic root of 28726857 is about 306.2640614396.

The spelling of 28726857 in words is "twenty-eight million, seven hundred twenty-six thousand, eight hundred fifty-seven".