28661578 has 16 divisors (see below), whose sum is σ = 47368800. Its totient is φ = 12898000.

The previous prime is 28661561. The next prime is 28661579. The reversal of 28661578 is 87516682.

It is not an unprimeable number, because it can be changed into a prime (28661579) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4228 + ... + 8671.

It is an arithmetic number, because the mean of its divisors is an integer number (2960550).

Almost surely, 2^28661578 is an apocalyptic number.

28661578 is a deficient number, since it is larger than the sum of its proper divisors (18707222).

28661578 is a wasteful number, since it uses less digits than its factorization.

28661578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13013.

The product of its digits is 161280, while the sum is 43.

The square root of 28661578 is about 5353.6509038225. The cubic root of 28661578 is about 306.0319003581.

It can be divided in two parts, 2866 and 1578, that added together give a palindrome (4444).

The spelling of 28661578 in words is "twenty-eight million, six hundred sixty-one thousand, five hundred seventy-eight".