13506021 has 10 divisors (see below), whose sum is σ = 20175782. Its totient is φ = 9003960.

The previous prime is 13506019. The next prime is 13506029. The reversal of 13506021 is 12060531.

13506021 is a `hidden beast` number, since 13 + 50 + 602 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12320100 + 1185921 = 3510^2 + 1089^2 .

It is not a de Polignac number, because 13506021 - 2¹ = 13506019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13505985 and 13506003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13506029) 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 9 ways as a sum of consecutive naturals, for example, 83290 + ... + 83451.

Almost surely, 2^13506021 is an apocalyptic number.

It is an amenable number.

13506021 is a deficient number, since it is larger than the sum of its proper divisors (6669761).

13506021 is an equidigital number, since it uses as much as digits as its factorization.

13506021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166753 (or 166744 counting only the distinct ones).

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

The square root of 13506021 is about 3675.0538771561. The cubic root of 13506021 is about 238.1455515773.

Adding to 13506021 its reverse (12060531), we get a palindrome (25566552).

The spelling of 13506021 in words is "thirteen million, five hundred six thousand, twenty-one".