13523991 has 16 divisors (see below), whose sum is σ = 20442240. Its totient is φ = 7884000.

The previous prime is 13523989. The next prime is 13523999. The reversal of 13523991 is 19932531.

13523991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13523991 - 2¹ = 13523989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13523999) 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 15 ways as a sum of consecutive naturals, for example, 8385 + ... + 9866.

It is an arithmetic number, because the mean of its divisors is an integer number (1277640).

Almost surely, 2^13523991 is an apocalyptic number.

13523991 is a deficient number, since it is larger than the sum of its proper divisors (6918249).

13523991 is a wasteful number, since it uses less digits than its factorization.

13523991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18286.

The product of its digits is 7290, while the sum is 33.

The square root of 13523991 is about 3677.4979265800. The cubic root of 13523991 is about 238.2511237265.

The spelling of 13523991 in words is "thirteen million, five hundred twenty-three thousand, nine hundred ninety-one".