21333329 has 2 divisors, whose sum is σ = 21333330. Its totient is φ = 21333328.

The previous prime is 21333271. The next prime is 21333353. The reversal of 21333329 is 92333312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20948929 + 384400 = 4577^2 + 620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21333329 - 2⁸ = 21333073 is a prime.

It is a super-2 number, since 2×21333329² = 910221852444482, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21333298 and 21333307.

It is not a weakly prime, because it can be changed into another prime (21332329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666664 + 10666665.

It is an arithmetic number, because the mean of its divisors is an integer number (10666665).

Almost surely, 2^21333329 is an apocalyptic number.

It is an amenable number.

21333329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21333329 is an equidigital number, since it uses as much as digits as its factorization.

21333329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 26.

The square root of 21333329 is about 4618.8016844199. The cubic root of 21333329 is about 277.3444909617.

It can be divided in two parts, 2 and 1333329, that added together give a palindrome (1333331).

The spelling of 21333329 in words is "twenty-one million, three hundred thirty-three thousand, three hundred twenty-nine".