13540221 has 6 divisors (see below), whose sum is σ = 19558110. Its totient is φ = 9026808.

The previous prime is 13540207. The next prime is 13540223. The reversal of 13540221 is 12204531.

It can be written as a sum of positive squares in only one way, i.e., 13505625 + 34596 = 3675^2 + 186^2 .

It is a de Polignac number, because none of the positive numbers 2^k-13540221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13540194 and 13540203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13540223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 752226 + ... + 752243.

It is an arithmetic number, because the mean of its divisors is an integer number (3259685).

Almost surely, 2^13540221 is an apocalyptic number.

It is an amenable number.

13540221 is a deficient number, since it is larger than the sum of its proper divisors (6017889).

13540221 is a wasteful number, since it uses less digits than its factorization.

13540221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1504475 (or 1504472 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 13540221 is about 3679.7039283073. The cubic root of 13540221 is about 238.3463931857.

Adding to 13540221 its reverse (12204531), we get a palindrome (25744752).

The spelling of 13540221 in words is "thirteen million, five hundred forty thousand, two hundred twenty-one".