21324329 has 4 divisors (see below), whose sum is σ = 22964676. Its totient is φ = 19683984.

The previous prime is 21324313. The next prime is 21324361. The reversal of 21324329 is 92342312.

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 13213225 + 8111104 = 3635^2 + 2848^2 .

It is a cyclic number.

It is not a de Polignac number, because 21324329 - 2⁴ = 21324313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21324298 and 21324307.

It is not an unprimeable number, because it can be changed into a prime (21324389) 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, 820154 + ... + 820179.

It is an arithmetic number, because the mean of its divisors is an integer number (5741169).

Almost surely, 2^21324329 is an apocalyptic number.

It is an amenable number.

21324329 is a deficient number, since it is larger than the sum of its proper divisors (1640347).

21324329 is a wasteful number, since it uses less digits than its factorization.

21324329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640346.

The product of its digits is 2592, while the sum is 26.

The square root of 21324329 is about 4617.8273029640. The cubic root of 21324329 is about 277.3054838989.

It can be divided in two parts, 213 and 24329, that added together give a palindrome (24542).

The spelling of 21324329 in words is "twenty-one million, three hundred twenty-four thousand, three hundred twenty-nine".