28239893281 has 16 divisors (see below), whose sum is σ = 31729968000. Its totient is φ = 24992205568.

The previous prime is 28239893257. The next prime is 28239893299. The reversal of 28239893281 is 18239893282.

It is a cyclic number.

It is not a de Polignac number, because 28239893281 - 2⁷ = 28239893153 is a prime.

It is a super-2 number, since 2×28239893281² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28239893081) 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, 589006 + ... + 635143.

It is an arithmetic number, because the mean of its divisors is an integer number (1983123000).

Almost surely, 2^28239893281 is an apocalyptic number.

It is an amenable number.

28239893281 is a deficient number, since it is larger than the sum of its proper divisors (3490074719).

28239893281 is a wasteful number, since it uses less digits than its factorization.

28239893281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1224248.

The product of its digits is 2985984, while the sum is 55.

Subtracting from 28239893281 its reverse (18239893282), we obtain a palindrome (9999999999).

The spelling of 28239893281 in words is "twenty-eight billion, two hundred thirty-nine million, eight hundred ninety-three thousand, two hundred eighty-one".