12090981681 has 9 divisors (see below), whose sum is σ = 17465227819. Its totient is φ = 8060434536.

The previous prime is 12090981659. The next prime is 12090981691. The reversal of 12090981681 is 18618909021.

The square root of 12090981681 is 109959.

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., 4846248225 + 7244733456 = 69615^2 + 85116^2 .

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

It is not a de Polignac number, because 12090981681 - 2¹¹ = 12090979633 is a prime.

It is a super-2 number, since 2×12090981681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12090981601) 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, 311551 + ... + 348203.

Almost surely, 2^12090981681 is an apocalyptic number.

12090981681 is the 109959-th square number.

12090981681 is the 54980-th centered octagonal number.

It is an amenable number.

12090981681 is a deficient number, since it is larger than the sum of its proper divisors (5374246138).

12090981681 is an frugal number, since it uses more digits than its factorization.

12090981681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73312 (or 36656 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 45.

The spelling of 12090981681 in words is "twelve billion, ninety million, nine hundred eighty-one thousand, six hundred eighty-one".