221261 has 2 divisors, whose sum is σ = 221262. Its totient is φ = 221260.

The previous prime is 221251. The next prime is 221281. The reversal of 221261 is 162122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 361 = 470^2 + 19^2 .

It is a cyclic number.

It is not a de Polignac number, because 221261 - 2⁶ = 221197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110630 + 110631.

It is an arithmetic number, because the mean of its divisors is an integer number (110631).

2²²¹²⁶¹ is an apocalyptic number.

It is an amenable number.

221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

221261 is an equidigital number, since it uses as much as digits as its factorization.

221261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48, while the sum is 14.

The square root of 221261 is about 470.3838857784. The cubic root of 221261 is about 60.4832273702.

Adding to 221261 its reverse (162122), we get a palindrome (383383).

The spelling of 221261 in words is "two hundred twenty-one thousand, two hundred sixty-one".