11261373505209 has 9 divisors (see below), whose sum is σ = 16266442938213. Its totient is φ = 7507575625212.

The previous prime is 11261373505181. The next prime is 11261373505279. The reversal of 11261373505209 is 90250537316211.

The square root of 11261373505209 is 3355797.

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

11261373505209 is a `hidden beast` number, since 1 + 1 + 2 + 6 + 1 + 3 + 73 + 50 + 520 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 11261373505209 - 2²⁷ = 11261239287481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11261373505279) 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, 9508092 + ... + 10626690.

Almost surely, 2^{11261373505209} is an apocalyptic number.

11261373505209 is the 3355797-th square number.

11261373505209 is the 1677899-th centered octagonal number.

It is an amenable number.

11261373505209 is a deficient number, since it is larger than the sum of its proper divisors (5005069433004).

11261373505209 is an frugal number, since it uses more digits than its factorization.

11261373505209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2237204 (or 1118602 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 11261373505209 in words is "eleven trillion, two hundred sixty-one billion, three hundred seventy-three million, five hundred five thousand, two hundred nine".