221993069 has 2 divisors, whose sum is σ = 221993070. Its totient is φ = 221993068.

The previous prime is 221993027. The next prime is 221993071. The reversal of 221993069 is 960399122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 142515844 + 79477225 = 11938^2 + 8915^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221993069 is a prime.

It is a super-2 number, since 2×221993069² = 98561845368077522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 221993071, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221993669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110996534 + 110996535.

It is an arithmetic number, because the mean of its divisors is an integer number (110996535).

Almost surely, 2^221993069 is an apocalyptic number.

It is an amenable number.

221993069 is a deficient number, since it is larger than the sum of its proper divisors (1).

221993069 is an equidigital number, since it uses as much as digits as its factorization.

221993069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 41.

The square root of 221993069 is about 14899.4318348050. The cubic root of 221993069 is about 605.4985931525.

The spelling of 221993069 in words is "two hundred twenty-one million, nine hundred ninety-three thousand, sixty-nine".