21613117 has 4 divisors (see below), whose sum is σ = 21873600. Its totient is φ = 21352636.

The previous prime is 21613079. The next prime is 21613129. The reversal of 21613117 is 71131612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21613117 - 2⁷ = 21612989 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613157) 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 3 ways as a sum of consecutive naturals, for example, 130117 + ... + 130282.

It is an arithmetic number, because the mean of its divisors is an integer number (5468400).

Almost surely, 2^21613117 is an apocalyptic number.

It is an amenable number.

21613117 is a deficient number, since it is larger than the sum of its proper divisors (260483).

21613117 is an equidigital number, since it uses as much as digits as its factorization.

21613117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260482.

The product of its digits is 252, while the sum is 22.

The square root of 21613117 is about 4648.9909657903. The cubic root of 21613117 is about 278.5516924248.

Adding to 21613117 its reverse (71131612), we get a palindrome (92744729).

The spelling of 21613117 in words is "twenty-one million, six hundred thirteen thousand, one hundred seventeen".