221235997 has 2 divisors, whose sum is σ = 221235998. Its totient is φ = 221235996.

The previous prime is 221235979. The next prime is 221236009. The reversal of 221235997 is 799532122.

Together with previous prime (221235979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221235876 + 121 = 14874^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 221235997 - 2⁷ = 221235869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221235947) 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, 110617998 + 110617999.

It is an arithmetic number, because the mean of its divisors is an integer number (110617999).

Almost surely, 2^221235997 is an apocalyptic number.

It is an amenable number.

221235997 is a deficient number, since it is larger than the sum of its proper divisors (1).

221235997 is an equidigital number, since it uses as much as digits as its factorization.

221235997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 40.

The square root of 221235997 is about 14874.0040674998. The cubic root of 221235997 is about 604.8094903658.

The spelling of 221235997 in words is "two hundred twenty-one million, two hundred thirty-five thousand, nine hundred ninety-seven".