21332413 has 4 divisors (see below), whose sum is σ = 21460320. Its totient is φ = 21204508.

The previous prime is 21332401. The next prime is 21332417. The reversal of 21332413 is 31423312.

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 21332413 - 2⁹ = 21331901 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 (21332417) 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, 63703 + ... + 64036.

It is an arithmetic number, because the mean of its divisors is an integer number (5365080).

Almost surely, 2^21332413 is an apocalyptic number.

It is an amenable number.

21332413 is a deficient number, since it is larger than the sum of its proper divisors (127907).

21332413 is a wasteful number, since it uses less digits than its factorization.

21332413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127906.

The product of its digits is 432, while the sum is 19.

The square root of 21332413 is about 4618.7025234366. The cubic root of 21332413 is about 277.3405214111.

Adding to 21332413 its reverse (31423312), we get a palindrome (52755725).

The spelling of 21332413 in words is "twenty-one million, three hundred thirty-two thousand, four hundred thirteen".