21327613 has 16 divisors (see below), whose sum is σ = 22784256. Its totient is φ = 19938240.

The previous prime is 21327611. The next prime is 21327617. The reversal of 21327613 is 31672312.

It is not a de Polignac number, because 21327613 - 2¹ = 21327611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21327611) 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, 123195 + ... + 123367.

It is an arithmetic number, because the mean of its divisors is an integer number (1424016).

Almost surely, 2^21327613 is an apocalyptic number.

It is an amenable number.

21327613 is a deficient number, since it is larger than the sum of its proper divisors (1456643).

21327613 is a wasteful number, since it uses less digits than its factorization.

21327613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324.

The product of its digits is 1512, while the sum is 25.

The square root of 21327613 is about 4618.1828677522. The cubic root of 21327613 is about 277.3197184142.

Adding to 21327613 its reverse (31672312), we get a palindrome (52999925).

The spelling of 21327613 in words is "twenty-one million, three hundred twenty-seven thousand, six hundred thirteen".