21380329 has 2 divisors, whose sum is σ = 21380330. Its totient is φ = 21380328.

The previous prime is 21380321. The next prime is 21380341. The reversal of 21380329 is 92308312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17239104 + 4141225 = 4152^2 + 2035^2 .

It is a cyclic number.

It is not a de Polignac number, because 21380329 - 2³ = 21380321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21380297 and 21380306.

It is not a weakly prime, because it can be changed into another prime (21380321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10690164 + 10690165.

It is an arithmetic number, because the mean of its divisors is an integer number (10690165).

Almost surely, 2^21380329 is an apocalyptic number.

It is an amenable number.

21380329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21380329 is an equidigital number, since it uses as much as digits as its factorization.

21380329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21380329 is about 4623.8867849462. The cubic root of 21380329 is about 277.5480164727.

The spelling of 21380329 in words is "twenty-one million, three hundred eighty thousand, three hundred twenty-nine".