13447681 has 8 divisors (see below), whose sum is σ = 14521640. Its totient is φ = 12379392.

The previous prime is 13447673. The next prime is 13447699. The reversal of 13447681 is 18674431.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 379456 + 13068225 = 616^2 + 3615^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13447681 - 2³ = 13447673 is a prime.

It is a super-2 number, since 2×13447681² = 361680248555522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13417681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4435 + ... + 6823.

It is an arithmetic number, because the mean of its divisors is an integer number (1815205).

Almost surely, 2^13447681 is an apocalyptic number.

It is an amenable number.

13447681 is a deficient number, since it is larger than the sum of its proper divisors (1073959).

13447681 is a wasteful number, since it uses less digits than its factorization.

13447681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2835.

The product of its digits is 16128, while the sum is 34.

The square root of 13447681 is about 3667.1079885926. The cubic root of 13447681 is about 237.8021624061.

It can be divided in two parts, 1344 and 7681, that added together give a square (9025 = 95²).

The spelling of 13447681 in words is "thirteen million, four hundred forty-seven thousand, six hundred eighty-one".