28782081 has 16 divisors (see below), whose sum is σ = 42724800. Its totient is φ = 19149984.

The previous prime is 28782079. The next prime is 28782101. The reversal of 28782081 is 18028782.

It is not a de Polignac number, because 28782081 - 2¹ = 28782079 is a prime.

It is a super-2 number, since 2×28782081² = 1656816373381122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28782031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21685 + ... + 22973.

It is an arithmetic number, because the mean of its divisors is an integer number (2670300).

Almost surely, 2^28782081 is an apocalyptic number.

It is an amenable number.

28782081 is a deficient number, since it is larger than the sum of its proper divisors (13942719).

28782081 is a wasteful number, since it uses less digits than its factorization.

28782081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2125 (or 2119 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 28782081 is about 5364.8933819788. The cubic root of 28782081 is about 306.4601880150.

The spelling of 28782081 in words is "twenty-eight million, seven hundred eighty-two thousand, eighty-one".