21910123 has 2 divisors, whose sum is σ = 21910124. Its totient is φ = 21910122.

The previous prime is 21910121. The next prime is 21910157. The reversal of 21910123 is 32101912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21910123 - 2¹ = 21910121 is a prime.

Together with 21910121, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21910123.

It is not a weakly prime, because it can be changed into another prime (21910121) 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, 10955061 + 10955062.

It is an arithmetic number, because the mean of its divisors is an integer number (10955062).

Almost surely, 2^21910123 is an apocalyptic number.

21910123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21910123 is an equidigital number, since it uses as much as digits as its factorization.

21910123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21910123 is about 4680.8250341152. The cubic root of 21910123 is about 279.8218381917.

The spelling of 21910123 in words is "twenty-one million, nine hundred ten thousand, one hundred twenty-three".