21126613 has 8 divisors (see below), whose sum is σ = 22295520. Its totient is φ = 19963440.

The previous prime is 21126607. The next prime is 21126617. The reversal of 21126613 is 31662112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21126613 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 (21126617) 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 7 ways as a sum of consecutive naturals, for example, 7683 + ... + 10063.

It is an arithmetic number, because the mean of its divisors is an integer number (2786940).

Almost surely, 2^21126613 is an apocalyptic number.

It is an amenable number.

21126613 is a deficient number, since it is larger than the sum of its proper divisors (1168907).

21126613 is a wasteful number, since it uses less digits than its factorization.

21126613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2867.

The product of its digits is 432, while the sum is 22.

The square root of 21126613 is about 4596.3695456306. The cubic root of 21126613 is about 276.4457763343.

Adding to 21126613 its reverse (31662112), we get a palindrome (52788725).

The spelling of 21126613 in words is "twenty-one million, one hundred twenty-six thousand, six hundred thirteen".