28561538 has 16 divisors (see below), whose sum is σ = 45066240. Its totient is φ = 13549536.

The previous prime is 28561531. The next prime is 28561609. The reversal of 28561538 is 83516582.

It is a super-2 number, since 2×28561538² = 1631522905850888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28561531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3398 + ... + 8286.

It is an arithmetic number, because the mean of its divisors is an integer number (2816640).

Almost surely, 2^28561538 is an apocalyptic number.

28561538 is a deficient number, since it is larger than the sum of its proper divisors (16504702).

28561538 is a wasteful number, since it uses less digits than its factorization.

28561538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5041.

The product of its digits is 57600, while the sum is 38.

The square root of 28561538 is about 5344.2995799263. The cubic root of 28561538 is about 305.6754287029.

The spelling of 28561538 in words is "twenty-eight million, five hundred sixty-one thousand, five hundred thirty-eight".