221966057 has 2 divisors, whose sum is σ = 221966058. Its totient is φ = 221966056.

The previous prime is 221966023. The next prime is 221966081. The reversal of 221966057 is 750669122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158030041 + 63936016 = 12571^2 + 7996^2 .

It is a cyclic number.

It is not a de Polignac number, because 221966057 - 2²⁰ = 220917481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221966057.

It is not a weakly prime, because it can be changed into another prime (221966557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110983028 + 110983029.

It is an arithmetic number, because the mean of its divisors is an integer number (110983029).

Almost surely, 2^221966057 is an apocalyptic number.

It is an amenable number.

221966057 is a deficient number, since it is larger than the sum of its proper divisors (1).

221966057 is an equidigital number, since it uses as much as digits as its factorization.

221966057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 221966057 is about 14898.5253297096. The cubic root of 221966057 is about 605.4740332394.

The spelling of 221966057 in words is "two hundred twenty-one million, nine hundred sixty-six thousand, fifty-seven".