221662261 has 2 divisors, whose sum is σ = 221662262. Its totient is φ = 221662260.

The previous prime is 221662253. The next prime is 221662279. The reversal of 221662261 is 162266122.

221662261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182412036 + 39250225 = 13506^2 + 6265^2 .

It is a cyclic number.

It is not a de Polignac number, because 221662261 - 2³ = 221662253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221662241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110831130 + 110831131.

It is an arithmetic number, because the mean of its divisors is an integer number (110831131).

Almost surely, 2^221662261 is an apocalyptic number.

It is an amenable number.

221662261 is a deficient number, since it is larger than the sum of its proper divisors (1).

221662261 is an equidigital number, since it uses as much as digits as its factorization.

221662261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 28.

The square root of 221662261 is about 14888.3263330705. The cubic root of 221662261 is about 605.1976778165.

The spelling of 221662261 in words is "two hundred twenty-one million, six hundred sixty-two thousand, two hundred sixty-one".