21330005 has 8 divisors (see below), whose sum is σ = 25666872. Its totient is φ = 17016768.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330005 is 50003312.

It can be written as a sum of positive squares in 4 ways, for example, as 1196836 + 20133169 = 1094^2 + 4487^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21330005 - 2²⁴ = 4552789 is a prime.

It is a super-2 number, since 2×21330005² = 909938226600050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3854 + ... + 7583.

It is an arithmetic number, because the mean of its divisors is an integer number (3208359).

Almost surely, 2^21330005 is an apocalyptic number.

It is an amenable number.

21330005 is a deficient number, since it is larger than the sum of its proper divisors (4336867).

21330005 is a wasteful number, since it uses less digits than its factorization.

21330005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11815.

The product of its (nonzero) digits is 90, while the sum is 14.

The square root of 21330005 is about 4618.4418368103. The cubic root of 21330005 is about 277.3300856311.

Adding to 21330005 its reverse (50003312), we get a palindrome (71333317).

The spelling of 21330005 in words is "twenty-one million, three hundred thirty thousand, five".