28881793 has 18 divisors (see below), whose sum is σ = 31964226. Its totient is φ = 26085888.

The previous prime is 28881791. The next prime is 28881803. The reversal of 28881793 is 39718882.

It can be written as a sum of positive squares in 9 ways, for example, as 4210704 + 24671089 = 2052^2 + 4967^2 .

It is not a de Polignac number, because 28881793 - 2¹ = 28881791 is a prime.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28881791) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 395605 + ... + 395677.

Almost surely, 2^28881793 is an apocalyptic number.

It is an amenable number.

28881793 is a deficient number, since it is larger than the sum of its proper divisors (3082433).

28881793 is an equidigital number, since it uses as much as digits as its factorization.

28881793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181 (or 127 counting only the distinct ones).

The product of its digits is 193536, while the sum is 46.

The square root of 28881793 is about 5374.1783558047. The cubic root of 28881793 is about 306.8136780697.

The spelling of 28881793 in words is "twenty-eight million, eight hundred eighty-one thousand, seven hundred ninety-three".