28143591 has 12 divisors (see below), whose sum is σ = 43651512. Its totient is φ = 16081968.

The previous prime is 28143571. The next prime is 28143607. The reversal of 28143591 is 19534182.

It is not a de Polignac number, because 28143591 - 2⁶ = 28143527 is a prime.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28143571) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95580 + ... + 95873.

It is an arithmetic number, because the mean of its divisors is an integer number (3637626).

Almost surely, 2^28143591 is an apocalyptic number.

28143591 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28143591 is a deficient number, since it is larger than the sum of its proper divisors (15507921).

28143591 is a wasteful number, since it uses less digits than its factorization.

28143591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191470 (or 191463 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 28143591 is about 5305.0533456319. The cubic root of 28143591 is about 304.1770919635.

The spelling of 28143591 in words is "twenty-eight million, one hundred forty-three thousand, five hundred ninety-one".