221993071 has 2 divisors, whose sum is σ = 221993072. Its totient is φ = 221993070.

The previous prime is 221993069. The next prime is 221993087. The reversal of 221993071 is 170399122.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221993071 - 2¹ = 221993069 is a prime.

It is a super-2 number, since 2×221993071² = 98561847144022082, which contains 22 as substring.

Together with 221993069, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221993011) 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, 110996535 + 110996536.

It is an arithmetic number, because the mean of its divisors is an integer number (110996536).

Almost surely, 2^221993071 is an apocalyptic number.

221993071 is a deficient number, since it is larger than the sum of its proper divisors (1).

221993071 is an equidigital number, since it uses as much as digits as its factorization.

221993071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 221993071 is about 14899.4319019216. The cubic root of 221993071 is about 605.4985949708.

The spelling of 221993071 in words is "two hundred twenty-one million, nine hundred ninety-three thousand, seventy-one".