221064541 has 2 divisors, whose sum is σ = 221064542. Its totient is φ = 221064540.

The previous prime is 221064539. The next prime is 221064553. The reversal of 221064541 is 145460122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209815225 + 11249316 = 14485^2 + 3354^2 .

It is a cyclic number.

It is not a de Polignac number, because 221064541 - 2¹ = 221064539 is a prime.

Together with 221064539, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221064511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110532270 + 110532271.

It is an arithmetic number, because the mean of its divisors is an integer number (110532271).

Almost surely, 2^221064541 is an apocalyptic number.

It is an amenable number.

221064541 is a deficient number, since it is larger than the sum of its proper divisors (1).

221064541 is an equidigital number, since it uses as much as digits as its factorization.

221064541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 221064541 is about 14868.2393375948. The cubic root of 221064541 is about 604.6532092643.

The spelling of 221064541 in words is "two hundred twenty-one million, sixty-four thousand, five hundred forty-one".