28091644 has 12 divisors (see below), whose sum is σ = 56183344. Its totient is φ = 12039264.

The previous prime is 28091629. The next prime is 28091663. The reversal of 28091644 is 44619082.

28091644 is an admirable number.

It is a congruent 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, 501609 + ... + 501664.

Almost surely, 2^28091644 is an apocalyptic number.

It is an amenable number.

28091644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28091644 is a wasteful number, since it uses less digits than its factorization.

28091644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1003284 (or 1003282 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28091644 is about 5300.1550920704. The cubic root of 28091644 is about 303.9898282608.

The spelling of 28091644 in words is "twenty-eight million, ninety-one thousand, six hundred forty-four".