21956323 has 2 divisors, whose sum is σ = 21956324. Its totient is φ = 21956322.

The previous prime is 21956321. The next prime is 21956351. The reversal of 21956323 is 32365912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21956323 - 2¹ = 21956321 is a prime.

Together with 21956321, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21956321) 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, 10978161 + 10978162.

It is an arithmetic number, because the mean of its divisors is an integer number (10978162).

Almost surely, 2^21956323 is an apocalyptic number.

21956323 is a deficient number, since it is larger than the sum of its proper divisors (1).

21956323 is an equidigital number, since it uses as much as digits as its factorization.

21956323 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 31.

The square root of 21956323 is about 4685.7574627802. The cubic root of 21956323 is about 280.0183788956.

The spelling of 21956323 in words is "twenty-one million, nine hundred fifty-six thousand, three hundred twenty-three".