28887745 has 4 divisors (see below), whose sum is σ = 34665300. Its totient is φ = 23110192.

The previous prime is 28887707. The next prime is 28887767. The reversal of 28887745 is 54778882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54778882 = 2 ⋅27389441.

It can be written as a sum of positive squares in 2 ways, for example, as 14508481 + 14379264 = 3809^2 + 3792^2 .

It is a cyclic number.

It is not a de Polignac number, because 28887745 - 2¹⁹ = 28363457 is a prime.

It is a super-2 number, since 2×28887745² = 1669003622370050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2888770 + ... + 2888779.

It is an arithmetic number, because the mean of its divisors is an integer number (8666325).

Almost surely, 2^28887745 is an apocalyptic number.

It is an amenable number.

28887745 is a deficient number, since it is larger than the sum of its proper divisors (5777555).

28887745 is an equidigital number, since it uses as much as digits as its factorization.

28887745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5777554.

The product of its digits is 1003520, while the sum is 49.

The square root of 28887745 is about 5374.7320863463. The cubic root of 28887745 is about 306.8347528183.

The spelling of 28887745 in words is "twenty-eight million, eight hundred eighty-seven thousand, seven hundred forty-five".