221491423 has 2 divisors, whose sum is σ = 221491424. Its totient is φ = 221491422.

The previous prime is 221491397. The next prime is 221491433. The reversal of 221491423 is 324194122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221491423 - 2⁹ = 221490911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221491391 and 221491400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221491433) 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, 110745711 + 110745712.

It is an arithmetic number, because the mean of its divisors is an integer number (110745712).

Almost surely, 2^221491423 is an apocalyptic number.

221491423 is a deficient number, since it is larger than the sum of its proper divisors (1).

221491423 is an equidigital number, since it uses as much as digits as its factorization.

221491423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 28.

The square root of 221491423 is about 14882.5879133973. The cubic root of 221491423 is about 605.0421599379.

The spelling of 221491423 in words is "two hundred twenty-one million, four hundred ninety-one thousand, four hundred twenty-three".