221966081 has 2 divisors, whose sum is σ = 221966082. Its totient is φ = 221966080.

The previous prime is 221966057. The next prime is 221966111. The reversal of 221966081 is 180669122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201895681 + 20070400 = 14209^2 + 4480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221966081 is a prime.

It is a super-2 number, since 2×221966081² = 98537882228997122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221966681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110983040 + 110983041.

It is an arithmetic number, because the mean of its divisors is an integer number (110983041).

Almost surely, 2^221966081 is an apocalyptic number.

It is an amenable number.

221966081 is a deficient number, since it is larger than the sum of its proper divisors (1).

221966081 is an equidigital number, since it uses as much as digits as its factorization.

221966081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 221966081 is about 14898.5261351585. The cubic root of 221966081 is about 605.4740550616.

The spelling of 221966081 in words is "two hundred twenty-one million, nine hundred sixty-six thousand, eighty-one".