21132413 has 4 divisors (see below), whose sum is σ = 21478908. Its totient is φ = 20785920.

The previous prime is 21132383. The next prime is 21132481. The reversal of 21132413 is 31423112.

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 683929 + 20448484 = 827^2 + 4522^2 .

It is a cyclic number.

It is not a de Polignac number, because 21132413 - 2¹⁰ = 21131389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21132391 and 21132400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132493) 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, 173156 + ... + 173277.

It is an arithmetic number, because the mean of its divisors is an integer number (5369727).

Almost surely, 2^21132413 is an apocalyptic number.

It is an amenable number.

21132413 is a deficient number, since it is larger than the sum of its proper divisors (346495).

21132413 is an equidigital number, since it uses as much as digits as its factorization.

21132413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346494.

The product of its digits is 144, while the sum is 17.

The square root of 21132413 is about 4597.0004350663. Note that the first 3 decimals coincide. The cubic root of 21132413 is about 276.4710720564.

Adding to 21132413 its reverse (31423112), we get a palindrome (52555525).

The spelling of 21132413 in words is "twenty-one million, one hundred thirty-two thousand, four hundred thirteen".