28126828381 has 4 divisors (see below), whose sum is σ = 28147196764. Its totient is φ = 28106460000.

The previous prime is 28126828369. The next prime is 28126828393. The reversal of 28126828381 is 18382862182.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28126828369) and next prime (28126828393).

It can be written as a sum of positive squares in 2 ways, for example, as 11217987225 + 16908841156 = 105915^2 + 130034^2 .

It is a cyclic number.

It is not a de Polignac number, because 28126828381 - 2¹¹ = 28126826333 is a prime.

It is a super-2 number, since 2×28126828381² (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 (28126828351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10182120 + ... + 10184881.

It is an arithmetic number, because the mean of its divisors is an integer number (7036799191).

Almost surely, 2^28126828381 is an apocalyptic number.

It is an amenable number.

28126828381 is a deficient number, since it is larger than the sum of its proper divisors (20368383).

28126828381 is a wasteful number, since it uses less digits than its factorization.

28126828381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20368382.

The product of its digits is 589824, while the sum is 49.

The spelling of 28126828381 in words is "twenty-eight billion, one hundred twenty-six million, eight hundred twenty-eight thousand, three hundred eighty-one".