28726881 has 16 divisors (see below), whose sum is σ = 39680256. Its totient is φ = 18473616.

The previous prime is 28726877. The next prime is 28726883. The reversal of 28726881 is 18862782.

It is not a de Polignac number, because 28726881 - 2² = 28726877 is a prime.

It is a super-2 number, since 2×28726881² = 1650467383976322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28726883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9366 + ... + 12048.

It is an arithmetic number, because the mean of its divisors is an integer number (2480016).

Almost surely, 2^28726881 is an apocalyptic number.

It is an amenable number.

28726881 is a deficient number, since it is larger than the sum of its proper divisors (10953375).

28726881 is a wasteful number, since it uses less digits than its factorization.

28726881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2812.

The product of its digits is 86016, while the sum is 42.

The square root of 28726881 is about 5359.7463559389. The cubic root of 28726881 is about 306.2641467295.

The spelling of 28726881 in words is "twenty-eight million, seven hundred twenty-six thousand, eight hundred eighty-one".