20556223 has 2 divisors, whose sum is σ = 20556224. Its totient is φ = 20556222.

The previous prime is 20556199. The next prime is 20556269. The reversal of 20556223 is 32265502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20556223 - 2⁵ = 20556191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20556023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10278111 + 10278112.

It is an arithmetic number, because the mean of its divisors is an integer number (10278112).

Almost surely, 2^20556223 is an apocalyptic number.

20556223 is a deficient number, since it is larger than the sum of its proper divisors (1).

20556223 is an equidigital number, since it uses as much as digits as its factorization.

20556223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 20556223 is about 4533.8971095516. The cubic root of 20556223 is about 273.9351570146.

The spelling of 20556223 in words is "twenty million, five hundred fifty-six thousand, two hundred twenty-three".