13446489681 has 9 divisors (see below), whose sum is σ = 19423209819. Its totient is φ = 8964094536.

The previous prime is 13446489671. The next prime is 13446489733. The reversal of 13446489681 is 18698464431.

The square root of 13446489681 is 115959.

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

13446489681 is a `hidden beast` number, since 13 + 4 + 464 + 8 + 96 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1144130625 + 12302359056 = 33825^2 + 110916^2 .

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

It is not a de Polignac number, because 13446489681 - 2⁵ = 13446489649 is a prime.

It is a super-2 number, since 2×13446489681² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13446489671) 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, 328551 + ... + 367203.

Almost surely, 2^13446489681 is an apocalyptic number.

13446489681 is the 115959-th square number.

13446489681 is the 57980-th centered octagonal number.

It is an amenable number.

13446489681 is a deficient number, since it is larger than the sum of its proper divisors (5976720138).

13446489681 is an frugal number, since it uses more digits than its factorization.

13446489681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77312 (or 38656 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The spelling of 13446489681 in words is "thirteen billion, four hundred forty-six million, four hundred eighty-nine thousand, six hundred eighty-one".