28751448781 has 16 divisors (see below), whose sum is σ = 33241527360. Its totient is φ = 24576986880.

The previous prime is 28751448757. The next prime is 28751448863. The reversal of 28751448781 is 18784415782.

It is a cyclic number.

It is not a de Polignac number, because 28751448781 - 2⁹ = 28751448269 is a prime.

It is a super-2 number, since 2×28751448781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28751443781) 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, 127990 + ... + 271816.

It is an arithmetic number, because the mean of its divisors is an integer number (2077595460).

Almost surely, 2^28751448781 is an apocalyptic number.

It is an amenable number.

28751448781 is a deficient number, since it is larger than the sum of its proper divisors (4490078579).

28751448781 is a wasteful number, since it uses less digits than its factorization.

28751448781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144924.

The product of its digits is 4014080, while the sum is 55.

The spelling of 28751448781 in words is "twenty-eight billion, seven hundred fifty-one million, four hundred forty-eight thousand, seven hundred eighty-one".