28785591 has 8 divisors (see below), whose sum is σ = 42645360. Its totient is φ = 19190376.

The previous prime is 28785587. The next prime is 28785599. The reversal of 28785591 is 19558782.

It is a happy number.

28785591 is a `hidden beast` number, since 28 + 78 + 559 + 1 = 666.

It is not a de Polignac number, because 28785591 - 2² = 28785587 is a prime.

It is a super-2 number, since 2×28785591² = 1657220498438562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28785599) 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, 533040 + ... + 533093.

It is an arithmetic number, because the mean of its divisors is an integer number (5330670).

Almost surely, 2^28785591 is an apocalyptic number.

28785591 is a deficient number, since it is larger than the sum of its proper divisors (13859769).

28785591 is a wasteful number, since it uses less digits than its factorization.

28785591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066142 (or 1066136 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The square root of 28785591 is about 5365.2204987307. The cubic root of 28785591 is about 306.4726452048.

The spelling of 28785591 in words is "twenty-eight million, seven hundred eighty-five thousand, five hundred ninety-one".