106664221 has 2 divisors, whose sum is σ = 106664222. Its totient is φ = 106664220.

The previous prime is 106664219. The next prime is 106664263. The reversal of 106664221 is 122466601.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97239321 + 9424900 = 9861^2 + 3070^2 .

It is a cyclic number.

It is not a de Polignac number, because 106664221 - 2¹ = 106664219 is a prime.

It is a super-2 number, since 2×106664221² = 22754512083073682, which contains 22 as substring.

Together with 106664219, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 106664221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (106644221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53332110 + 53332111.

It is an arithmetic number, because the mean of its divisors is an integer number (53332111).

Almost surely, 2^106664221 is an apocalyptic number.

It is an amenable number.

106664221 is a deficient number, since it is larger than the sum of its proper divisors (1).

106664221 is an equidigital number, since it uses as much as digits as its factorization.

106664221 is an evil number, because the sum of its binary digits is even.

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

The square root of 106664221 is about 10327.8371888794. The cubic root of 106664221 is about 474.2488159979.

The spelling of 106664221 in words is "one hundred six million, six hundred sixty-four thousand, two hundred twenty-one".