21800329 has 2 divisors, whose sum is σ = 21800330. Its totient is φ = 21800328.

The previous prime is 21800321. The next prime is 21800351. The reversal of 21800329 is 92300812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19404025 + 2396304 = 4405^2 + 1548^2 .

It is a cyclic number.

It is not a de Polignac number, because 21800329 - 2³ = 21800321 is a prime.

It is equal to p_1377403 and since 21800329 and 1377403 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21800321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10900164 + 10900165.

It is an arithmetic number, because the mean of its divisors is an integer number (10900165).

Almost surely, 2^21800329 is an apocalyptic number.

It is an amenable number.

21800329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21800329 is an equidigital number, since it uses as much as digits as its factorization.

21800329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21800329 is about 4669.0822438676. The cubic root of 21800329 is about 279.3536494218.

The spelling of 21800329 in words is "twenty-one million, eight hundred thousand, three hundred twenty-nine".