13947981 has 8 divisors (see below), whose sum is σ = 18681600. Its totient is φ = 9256512.

The previous prime is 13947977. The next prime is 13948019. The reversal of 13947981 is 18974931.

It is a happy number.

13947981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 13947981 - 2² = 13947977 is a prime.

It is a super-2 number, since 2×13947981² = 389092347952722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13947911) 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, 9756 + ... + 11093.

It is an arithmetic number, because the mean of its divisors is an integer number (2335200).

Almost surely, 2^13947981 is an apocalyptic number.

It is an amenable number.

13947981 is a deficient number, since it is larger than the sum of its proper divisors (4733619).

13947981 is a wasteful number, since it uses less digits than its factorization.

13947981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21075.

The product of its digits is 54432, while the sum is 42.

The square root of 13947981 is about 3734.6995863121. The cubic root of 13947981 is about 240.7153483403.

The spelling of 13947981 in words is "thirteen million, nine hundred forty-seven thousand, nine hundred eighty-one".