221242969 has 2 divisors, whose sum is σ = 221242970. Its totient is φ = 221242968.

The previous prime is 221242951. The next prime is 221242991. The reversal of 221242969 is 969242122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208369225 + 12873744 = 14435^2 + 3588^2 .

It is a cyclic number.

It is not a de Polignac number, because 221242969 - 2⁷ = 221242841 is a prime.

It is a super-2 number, since 2×221242969² = 97896902663869922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221242909) 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, 110621484 + 110621485.

It is an arithmetic number, because the mean of its divisors is an integer number (110621485).

Almost surely, 2^221242969 is an apocalyptic number.

It is an amenable number.

221242969 is a deficient number, since it is larger than the sum of its proper divisors (1).

221242969 is an equidigital number, since it uses as much as digits as its factorization.

221242969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 37.

The square root of 221242969 is about 14874.2384342863. The cubic root of 221242969 is about 604.8158435927.

The spelling of 221242969 in words is "two hundred twenty-one million, two hundred forty-two thousand, nine hundred sixty-nine".