221441681 has 2 divisors, whose sum is σ = 221441682. Its totient is φ = 221441680.

The previous prime is 221441663. The next prime is 221441699. The reversal of 221441681 is 186144122.

It is a balanced prime because it is at equal distance from previous prime (221441663) and next prime (221441699).

It can be written as a sum of positive squares in only one way, i.e., 164891281 + 56550400 = 12841^2 + 7520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221441681 is a prime.

It is a super-2 number, since 2×221441681² = 98072836168211522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221441621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110720840 + 110720841.

It is an arithmetic number, because the mean of its divisors is an integer number (110720841).

Almost surely, 2^221441681 is an apocalyptic number.

It is an amenable number.

221441681 is a deficient number, since it is larger than the sum of its proper divisors (1).

221441681 is an equidigital number, since it uses as much as digits as its factorization.

221441681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 29.

The square root of 221441681 is about 14880.9166720333. The cubic root of 221441681 is about 604.9968635860.

The spelling of 221441681 in words is "two hundred twenty-one million, four hundred forty-one thousand, six hundred eighty-one".