20911243 has 2 divisors, whose sum is σ = 20911244. Its totient is φ = 20911242.

The previous prime is 20911223. The next prime is 20911279. The reversal of 20911243 is 34211902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20911243 - 2⁵ = 20911211 is a prime.

It is not a weakly prime, because it can be changed into another prime (20911213) 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, 10455621 + 10455622.

It is an arithmetic number, because the mean of its divisors is an integer number (10455622).

Almost surely, 2^20911243 is an apocalyptic number.

20911243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20911243 is an equidigital number, since it uses as much as digits as its factorization.

20911243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20911243 is about 4572.8812580254. The cubic root of 20911243 is about 275.5031801241.

The spelling of 20911243 in words is "twenty million, nine hundred eleven thousand, two hundred forty-three".