21243329 has 8 divisors (see below), whose sum is σ = 22234560. Its totient is φ = 20257776.

The previous prime is 21243307. The next prime is 21243331. The reversal of 21243329 is 92334212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21243329 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21243298 and 21243307.

It is not an unprimeable number, because it can be changed into a prime (21243359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7499 + ... + 9935.

It is an arithmetic number, because the mean of its divisors is an integer number (2779320).

Almost surely, 2^21243329 is an apocalyptic number.

It is an amenable number.

21243329 is a deficient number, since it is larger than the sum of its proper divisors (991231).

21243329 is a wasteful number, since it uses less digits than its factorization.

21243329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839.

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

The square root of 21243329 is about 4609.0486003079. The cubic root of 21243329 is about 276.9539254432.

The spelling of 21243329 in words is "twenty-one million, two hundred forty-three thousand, three hundred twenty-nine".