28007881 has 16 divisors (see below), whose sum is σ = 33278400. Its totient is φ = 23284800.

The previous prime is 28007873. The next prime is 28007897. The reversal of 28007881 is 18870082.

It is not a de Polignac number, because 28007881 - 2³ = 28007873 is a prime.

It is a super-2 number, since 2×28007881² = 1568882796220322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28007821) 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, 3751 + ... + 8371.

It is an arithmetic number, because the mean of its divisors is an integer number (2079900).

Almost surely, 2^28007881 is an apocalyptic number.

It is an amenable number.

28007881 is a deficient number, since it is larger than the sum of its proper divisors (5270519).

28007881 is a wasteful number, since it uses less digits than its factorization.

28007881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4680.

The product of its (nonzero) digits is 7168, while the sum is 34.

The square root of 28007881 is about 5292.2472542390. The cubic root of 28007881 is about 303.6873842266.

The spelling of 28007881 in words is "twenty-eight million, seven thousand, eight hundred eighty-one".