21324659 has 4 divisors (see below), whose sum is σ = 21433104. Its totient is φ = 21216216.

The previous prime is 21324629. The next prime is 21324661. The reversal of 21324659 is 95642312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21324659 - 2¹⁶ = 21259123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21324619) 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, 53927 + ... + 54320.

It is an arithmetic number, because the mean of its divisors is an integer number (5358276).

Almost surely, 2^21324659 is an apocalyptic number.

21324659 is a deficient number, since it is larger than the sum of its proper divisors (108445).

21324659 is a wasteful number, since it uses less digits than its factorization.

21324659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108444.

The product of its digits is 12960, while the sum is 32.

The square root of 21324659 is about 4617.8630339151. The cubic root of 21324659 is about 277.3069143517.

The spelling of 21324659 in words is "twenty-one million, three hundred twenty-four thousand, six hundred fifty-nine".