26309813209 has 9 divisors (see below), whose sum is σ = 27770673567. Its totient is φ = 24922166544.

The previous prime is 26309813177. The next prime is 26309813219. The reversal of 26309813209 is 90231890362.

The square root of 26309813209 is 162203.

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., 23248625625 + 3061187584 = 152475^2 + 55328^2 .

It is not a de Polignac number, because 26309813209 - 2⁵ = 26309813177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26309813219) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3077589 + ... + 3086125.

Almost surely, 2^26309813209 is an apocalyptic number.

26309813209 is the 162203-rd square number.

26309813209 is the 81102-nd centered octagonal number.

It is an amenable number.

26309813209 is a deficient number, since it is larger than the sum of its proper divisors (1460860358).

26309813209 is an frugal number, since it uses more digits than its factorization.

26309813209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17112 (or 8556 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 26309813209 in words is "twenty-six billion, three hundred nine million, eight hundred thirteen thousand, two hundred nine".