21750329 has 2 divisors, whose sum is σ = 21750330. Its totient is φ = 21750328.

The previous prime is 21750301. The next prime is 21750347. The reversal of 21750329 is 92305712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14807104 + 6943225 = 3848^2 + 2635^2 .

It is a cyclic number.

It is not a de Polignac number, because 21750329 - 2⁸ = 21750073 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21750229) 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, 10875164 + 10875165.

It is an arithmetic number, because the mean of its divisors is an integer number (10875165).

Almost surely, 2^21750329 is an apocalyptic number.

It is an amenable number.

21750329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21750329 is an equidigital number, since it uses as much as digits as its factorization.

21750329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 21750329 is about 4663.7247989134. The cubic root of 21750329 is about 279.1399160328.

The spelling of 21750329 in words is "twenty-one million, seven hundred fifty thousand, three hundred twenty-nine".