21324641 has 8 divisors (see below), whose sum is σ = 23083200. Its totient is φ = 19582992.

The previous prime is 21324629. The next prime is 21324661. The reversal of 21324641 is 14642312.

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

It is a de Polignac number, because none of the positive numbers 2^k-21324641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21324661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1535 + ... + 6708.

It is an arithmetic number, because the mean of its divisors is an integer number (2885400).

Almost surely, 2^21324641 is an apocalyptic number.

It is an amenable number.

21324641 is a deficient number, since it is larger than the sum of its proper divisors (1758559).

21324641 is a wasteful number, since it uses less digits than its factorization.

21324641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8455.

The product of its digits is 1152, while the sum is 23.

The square root of 21324641 is about 4617.8610849613. The cubic root of 21324641 is about 277.3068363273.

Adding to 21324641 its reverse (14642312), we get a palindrome (35966953).

The spelling of 21324641 in words is "twenty-one million, three hundred twenty-four thousand, six hundred forty-one".