13447981 has 4 divisors (see below), whose sum is σ = 13484992. Its totient is φ = 13410972.

The previous prime is 13447963. The next prime is 13447997. The reversal of 13447981 is 18974431.

13447981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13447981 - 2⁷ = 13447853 is a prime.

It is a super-2 number, since 2×13447981² = 361696385952722, which 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 13447981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13447921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17955 + ... + 18688.

It is an arithmetic number, because the mean of its divisors is an integer number (3371248).

Almost surely, 2^13447981 is an apocalyptic number.

It is an amenable number.

13447981 is a deficient number, since it is larger than the sum of its proper divisors (37011).

13447981 is an equidigital number, since it uses as much as digits as its factorization.

13447981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37010.

The product of its digits is 24192, while the sum is 37.

The square root of 13447981 is about 3667.1488925322. The cubic root of 13447981 is about 237.8039307436.

The spelling of 13447981 in words is "thirteen million, four hundred forty-seven thousand, nine hundred eighty-one".