21629329 has 2 divisors, whose sum is σ = 21629330. Its totient is φ = 21629328.

The previous prime is 21629327. The next prime is 21629347. The reversal of 21629329 is 92392612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19820304 + 1809025 = 4452^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 21629329 - 2¹ = 21629327 is a prime.

Together with 21629327, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21629294 and 21629303.

It is not a weakly prime, because it can be changed into another prime (21629327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10814664 + 10814665.

It is an arithmetic number, because the mean of its divisors is an integer number (10814665).

Almost surely, 2^21629329 is an apocalyptic number.

It is an amenable number.

21629329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21629329 is an equidigital number, since it uses as much as digits as its factorization.

21629329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 34.

The square root of 21629329 is about 4650.7342431061. The cubic root of 21629329 is about 278.6213222301.

The spelling of 21629329 in words is "twenty-one million, six hundred twenty-nine thousand, three hundred twenty-nine".