11981573796481 has 9 divisors (see below), whose sum is σ = 12148209515721. Its totient is φ = 11817193424832.

The previous prime is 11981573796449. The next prime is 11981573796497. The reversal of 11981573796481 is 18469737518911.

It is a happy number.

The square root of 11981573796481 is 3461441.

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

11981573796481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1474381206081 + 10507192590400 = 1214241^2 + 3241480^2 .

It is not a de Polignac number, because 11981573796481 - 2⁵ = 11981573796449 is a prime.

It is a super-2 number, since 2×11981573796481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11981573796481.

It is not an unprimeable number, because it can be changed into a prime (11981573797481) 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, 252661485 + ... + 252708901.

Almost surely, 2^{11981573796481} is an apocalyptic number.

11981573796481 is the 3461441-st square number.

11981573796481 is the 1730721-st centered octagonal number.

It is an amenable number.

11981573796481 is a deficient number, since it is larger than the sum of its proper divisors (166635719240).

11981573796481 is an frugal number, since it uses more digits than its factorization.

11981573796481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94980 (or 47490 counting only the distinct ones).

The product of its digits is 91445760, while the sum is 70.

The spelling of 11981573796481 in words is "eleven trillion, nine hundred eighty-one billion, five hundred seventy-three million, seven hundred ninety-six thousand, four hundred eighty-one".