28138644683181 has 10 divisors (see below), whose sum is σ = 42034271687342. Its totient is φ = 18759096455400.

The previous prime is 28138644683143. The next prime is 28138644683231. The reversal of 28138644683181 is 18138644683182.

28138644683181 is a `hidden beast` number, since 2 + 8 + 1 + 3 + 8 + 6 + 446 + 8 + 3 + 181 = 666.

It can be written as a sum of positive squares in only one way, i.e., 27226793484900 + 911851198281 = 5217930^2 + 954909^2 .

It is not a de Polignac number, because 28138644683181 - 2⁷ = 28138644683053 is a prime.

It is a super-2 number, since 2×28138644683181² (a number of 28 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 (28138644683111) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 173695337470 + ... + 173695337631.

Almost surely, 2^{28138644683181} is an apocalyptic number.

It is an amenable number.

28138644683181 is a deficient number, since it is larger than the sum of its proper divisors (13895627004161).

28138644683181 is an equidigital number, since it uses as much as digits as its factorization.

28138644683181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347390675113 (or 347390675104 counting only the distinct ones).

The product of its digits is 42467328, while the sum is 63.

Subtracting from 28138644683181 its reverse (18138644683182), we obtain a palindrome (9999999999999).

The spelling of 28138644683181 in words is "twenty-eight trillion, one hundred thirty-eight billion, six hundred forty-four million, six hundred eighty-three thousand, one hundred eighty-one".