28857641 has 4 divisors (see below), whose sum is σ = 29122500. Its totient is φ = 28592784.

The previous prime is 28857629. The next prime is 28857643. The reversal of 28857641 is 14675882.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19616041 + 9241600 = 4429^2 + 3040^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28857641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28857643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132266 + ... + 132483.

It is an arithmetic number, because the mean of its divisors is an integer number (7280625).

Almost surely, 2^28857641 is an apocalyptic number.

It is an amenable number.

28857641 is a deficient number, since it is larger than the sum of its proper divisors (264859).

28857641 is a wasteful number, since it uses less digits than its factorization.

28857641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264858.

The product of its digits is 107520, while the sum is 41.

The square root of 28857641 is about 5371.9308446777. The cubic root of 28857641 is about 306.7281313210.

The spelling of 28857641 in words is "twenty-eight million, eight hundred fifty-seven thousand, six hundred forty-one".