28561771 has 4 divisors (see below), whose sum is σ = 32642032. Its totient is φ = 24481512.

The previous prime is 28561727. The next prime is 28561783. The reversal of 28561771 is 17716582.

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

It is a cyclic number.

It is not a de Polignac number, because 28561771 - 2¹¹ = 28559723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28561771.

It is not an unprimeable number, because it can be changed into a prime (28561271) 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, 2040120 + ... + 2040133.

It is an arithmetic number, because the mean of its divisors is an integer number (8160508).

Almost surely, 2^28561771 is an apocalyptic number.

28561771 is a deficient number, since it is larger than the sum of its proper divisors (4080261).

28561771 is an equidigital number, since it uses as much as digits as its factorization.

28561771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4080260.

The product of its digits is 23520, while the sum is 37.

The square root of 28561771 is about 5344.3213788095. The cubic root of 28561771 is about 305.6762599161.

The spelling of 28561771 in words is "twenty-eight million, five hundred sixty-one thousand, seven hundred seventy-one".