26781173552809 has 27 divisors (see below), whose sum is σ = 29377294160823. Its totient is φ = 24403314325104.

The previous prime is 26781173552803. The next prime is 26781173552813. The reversal of 26781173552809 is 90825537118762.

The square root of 26781173552809 is 5175053.

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

It can be written as a sum of positive squares in only one way, i.e., 3961712064025 + 22819461488784 = 1990405^2 + 4776972^2 .

It is not a de Polignac number, because 26781173552809 - 2¹⁵ = 26781173520041 is a prime.

It is a super-3 number, since 3×26781173552809³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26781173552803) 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 26 ways as a sum of consecutive naturals, for example, 5314776912 + ... + 5314781950.

Almost surely, 2^{26781173552809} is an apocalyptic number.

26781173552809 is the 5175053-rd square number.

26781173552809 is the 2587527-th centered octagonal number.

It is an amenable number.

26781173552809 is a deficient number, since it is larger than the sum of its proper divisors (2596120608014).

26781173552809 is an frugal number, since it uses more digits than its factorization.

26781173552809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10262 (or 5131 counting only the distinct ones).

The product of its (nonzero) digits is 50803200, while the sum is 64.

The spelling of 26781173552809 in words is "twenty-six trillion, seven hundred eighty-one billion, one hundred seventy-three million, five hundred fifty-two thousand, eight hundred nine".