20917223 has 2 divisors, whose sum is σ = 20917224. Its totient is φ = 20917222.

The previous prime is 20917187. The next prime is 20917229. The reversal of 20917223 is 32271902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20917223 - 2⁶ = 20917159 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20917192 and 20917201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20917229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10458611 + 10458612.

It is an arithmetic number, because the mean of its divisors is an integer number (10458612).

Almost surely, 2^20917223 is an apocalyptic number.

20917223 is a deficient number, since it is larger than the sum of its proper divisors (1).

20917223 is an equidigital number, since it uses as much as digits as its factorization.

20917223 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20917223 is about 4573.5350660075. The cubic root of 20917223 is about 275.5294395546.

The spelling of 20917223 in words is "twenty million, nine hundred seventeen thousand, two hundred twenty-three".