26851538331409 has 81 divisors (see below), whose sum is σ = 30690445426011. Its totient is φ = 23475010553280.

The previous prime is 26851538331407. The next prime is 26851538331427. The reversal of 26851538331409 is 90413383515862.

The square root of 26851538331409 is 5181847.

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., 5156064865809 + 21695473465600 = 2270697^2 + 4657840^2 .

It is not a de Polignac number, because 26851538331409 - 2¹ = 26851538331407 is a prime.

It is a super-2 number, since 2×26851538331409² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26851538331407) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 301702677837 + ... + 301702677925.

Almost surely, 2^{26851538331409} is an apocalyptic number.

26851538331409 is the 5181847-th square number.

26851538331409 is the 2590924-th centered octagonal number.

It is an amenable number.

26851538331409 is a deficient number, since it is larger than the sum of its proper divisors (3838907094602).

26851538331409 is an frugal number, since it uses more digits than its factorization.

26851538331409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 58.

The spelling of 26851538331409 in words is "twenty-six trillion, eight hundred fifty-one billion, five hundred thirty-eight million, three hundred thirty-one thousand, four hundred nine".