13506981 has 4 divisors (see below), whose sum is σ = 18009312. Its totient is φ = 9004652.

The previous prime is 13506973. The next prime is 13507009. The reversal of 13506981 is 18960531.

13506981 is digitally balanced in base 2, 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 13506981 - 2³ = 13506973 is a prime.

It is a super-2 number, since 2×13506981² = 364877071468722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13506901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2251161 + ... + 2251166.

It is an arithmetic number, because the mean of its divisors is an integer number (4502328).

Almost surely, 2^13506981 is an apocalyptic number.

It is an amenable number.

13506981 is a deficient number, since it is larger than the sum of its proper divisors (4502331).

13506981 is an equidigital number, since it uses as much as digits as its factorization.

13506981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4502330.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 13506981 is about 3675.1844851653. The cubic root of 13506981 is about 238.1511938587.

The spelling of 13506981 in words is "thirteen million, five hundred six thousand, nine hundred eighty-one".