221394541 has 2 divisors, whose sum is σ = 221394542. Its totient is φ = 221394540.

The previous prime is 221394533. The next prime is 221394557. The reversal of 221394541 is 145493122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208224900 + 13169641 = 14430^2 + 3629^2 .

It is a cyclic number.

It is not a de Polignac number, because 221394541 - 2³ = 221394533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221397541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110697270 + 110697271.

It is an arithmetic number, because the mean of its divisors is an integer number (110697271).

Almost surely, 2^221394541 is an apocalyptic number.

It is an amenable number.

221394541 is a deficient number, since it is larger than the sum of its proper divisors (1).

221394541 is an equidigital number, since it uses as much as digits as its factorization.

221394541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 221394541 is about 14879.3326799289. The cubic root of 221394541 is about 604.9539304218.

The spelling of 221394541 in words is "two hundred twenty-one million, three hundred ninety-four thousand, five hundred forty-one".