28971103681 has 9 divisors (see below), whose sum is σ = 31373472969. Its totient is φ = 26740514736.

The previous prime is 28971103663. The next prime is 28971103697. The reversal of 28971103681 is 18630117982.

It is a happy number.

The square root of 28971103681 is 170209.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 179801281 + 28791302400 = 13409^2 + 169680^2 .

It is not a de Polignac number, because 28971103681 - 2²³ = 28962715073 is a prime.

It is a super-2 number, since 2×28971103681² (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 (28971103181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2206171 + ... + 2219263.

It is an arithmetic number, because the mean of its divisors is an integer number (3485941441).

Almost surely, 2^28971103681 is an apocalyptic number.

28971103681 is the 170209-th square number.

28971103681 is the 85105-th centered octagonal number.

It is an amenable number.

28971103681 is a deficient number, since it is larger than the sum of its proper divisors (2402369288).

28971103681 is an frugal number, since it uses more digits than its factorization.

28971103681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26212 (or 13106 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 28971103681 in words is "twenty-eight billion, nine hundred seventy-one million, one hundred three thousand, six hundred eighty-one".