21347329 has 2 divisors, whose sum is σ = 21347330. Its totient is φ = 21347328.

The previous prime is 21347309. The next prime is 21347363. The reversal of 21347329 is 92374312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18722929 + 2624400 = 4327^2 + 1620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21347329 - 2⁵ = 21347297 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21347329.

It is not a weakly prime, because it can be changed into another prime (21347309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10673664 + 10673665.

It is an arithmetic number, because the mean of its divisors is an integer number (10673665).

Almost surely, 2^21347329 is an apocalyptic number.

It is an amenable number.

21347329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21347329 is an equidigital number, since it uses as much as digits as its factorization.

21347329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 31.

The square root of 21347329 is about 4620.3169804679. The cubic root of 21347329 is about 277.4051468149.

The spelling of 21347329 in words is "twenty-one million, three hundred forty-seven thousand, three hundred twenty-nine".