13213521 has 12 divisors (see below), whose sum is σ = 19552260. Its totient is φ = 8593920.

The previous prime is 13213507. The next prime is 13213547. The reversal of 13213521 is 12531231.

13213521 is a `hidden beast` number, since 132 + 13 + 521 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3101121 + 10112400 = 1761^2 + 3180^2 .

It is not a de Polignac number, because 13213521 - 2¹³ = 13205329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13213494 and 13213503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13213121) 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 11 ways as a sum of consecutive naturals, for example, 17536 + ... + 18273.

It is an arithmetic number, because the mean of its divisors is an integer number (1629355).

Almost surely, 2^13213521 is an apocalyptic number.

It is an amenable number.

13213521 is a deficient number, since it is larger than the sum of its proper divisors (6338739).

13213521 is a wasteful number, since it uses less digits than its factorization.

13213521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35856 (or 35853 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 13213521 is about 3635.0407150402. The cubic root of 13213521 is about 236.4138160048.

Adding to 13213521 its reverse (12531231), we get a palindrome (25744752).

The spelling of 13213521 in words is "thirteen million, two hundred thirteen thousand, five hundred twenty-one".