221235869 has 2 divisors, whose sum is σ = 221235870. Its totient is φ = 221235868.

The previous prime is 221235853. The next prime is 221235881. The reversal of 221235869 is 968532122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166668100 + 54567769 = 12910^2 + 7387^2 .

It is a cyclic number.

It is not a de Polignac number, because 221235869 - 2⁴ = 221235853 is a prime.

It is a super-2 number, since 2×221235869² = 97890619464370322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221235769) 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, 110617934 + 110617935.

It is an arithmetic number, because the mean of its divisors is an integer number (110617935).

Almost surely, 2^221235869 is an apocalyptic number.

It is an amenable number.

221235869 is a deficient number, since it is larger than the sum of its proper divisors (1).

221235869 is an equidigital number, since it uses as much as digits as its factorization.

221235869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 38.

The square root of 221235869 is about 14873.9997646901. Note that the first 3 decimals coincide. The cubic root of 221235869 is about 604.8093737247.

The spelling of 221235869 in words is "two hundred twenty-one million, two hundred thirty-five thousand, eight hundred sixty-nine".