13521431 has 16 divisors (see below), whose sum is σ = 17273088. Its totient is φ = 10276800.

The previous prime is 13521421. The next prime is 13521437. The reversal of 13521431 is 13412531.

13521431 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 13521431 - 2⁶ = 13521367 is a prime.

It is a super-3 number, since 3×13521431³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

13521431 is strictly pandigital in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13521437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1016 + ... + 5298.

It is an arithmetic number, because the mean of its divisors is an integer number (1079568).

Almost surely, 2^13521431 is an apocalyptic number.

13521431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13521431 is a deficient number, since it is larger than the sum of its proper divisors (3751657).

13521431 is a wasteful number, since it uses less digits than its factorization.

13521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4342.

The product of its digits is 360, while the sum is 20.

The square root of 13521431 is about 3677.1498473682. The cubic root of 13521431 is about 238.2360896692.

Adding to 13521431 its reverse (13412531), we get a palindrome (26933962).

Subtracting from 13521431 its reverse (13412531), we obtain a square (108900 = 330²).

The spelling of 13521431 in words is "thirteen million, five hundred twenty-one thousand, four hundred thirty-one".