21975329 has 4 divisors (see below), whose sum is σ = 22240176. Its totient is φ = 21710484.

The previous prime is 21975323. The next prime is 21975347. The reversal of 21975329 is 92357912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21975329 - 2⁴ = 21975313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21975292 and 21975301.

It is not an unprimeable number, because it can be changed into a prime (21975323) 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 in 3 ways as a sum of consecutive naturals, for example, 132299 + ... + 132464.

It is an arithmetic number, because the mean of its divisors is an integer number (5560044).

Almost surely, 2^21975329 is an apocalyptic number.

It is an amenable number.

21975329 is a deficient number, since it is larger than the sum of its proper divisors (264847).

21975329 is an equidigital number, since it uses as much as digits as its factorization.

21975329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264846.

The product of its digits is 34020, while the sum is 38.

The square root of 21975329 is about 4687.7850846642. The cubic root of 21975329 is about 280.0991528093.

The spelling of 21975329 in words is "twenty-one million, nine hundred seventy-five thousand, three hundred twenty-nine".