21412613 has 4 divisors (see below), whose sum is σ = 21429708. Its totient is φ = 21395520.

The previous prime is 21412591. The next prime is 21412621. The reversal of 21412613 is 31621412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2896804 + 18515809 = 1702^2 + 4303^2 .

It is a cyclic number.

It is not a de Polignac number, because 21412613 - 2⁶ = 21412549 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 (21412663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6506 + ... + 9227.

It is an arithmetic number, because the mean of its divisors is an integer number (5357427).

Almost surely, 2^21412613 is an apocalyptic number.

It is an amenable number.

21412613 is a deficient number, since it is larger than the sum of its proper divisors (17095).

21412613 is a wasteful number, since it uses less digits than its factorization.

21412613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17094.

The product of its digits is 288, while the sum is 20.

The square root of 21412613 is about 4627.3764705284. The cubic root of 21412613 is about 277.6876441017.

The spelling of 21412613 in words is "twenty-one million, four hundred twelve thousand, six hundred thirteen".