21446329 has 2 divisors, whose sum is σ = 21446330. Its totient is φ = 21446328.

The previous prime is 21446317. The next prime is 21446339. The reversal of 21446329 is 92364412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 1375929 = 4480^2 + 1173^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21446329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21446329.

It is not a weakly prime, because it can be changed into another prime (21446309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723164 + 10723165.

It is an arithmetic number, because the mean of its divisors is an integer number (10723165).

Almost surely, 2^21446329 is an apocalyptic number.

It is an amenable number.

21446329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21446329 is an equidigital number, since it uses as much as digits as its factorization.

21446329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 31.

The square root of 21446329 is about 4631.0181385954. The cubic root of 21446329 is about 277.8333153605.

The spelling of 21446329 in words is "twenty-one million, four hundred forty-six thousand, three hundred twenty-nine".