1066220221 has 4 divisors (see below), whose sum is σ = 1163149344. Its totient is φ = 969291100.

The previous prime is 1066220219. The next prime is 1066220237. The reversal of 1066220221 is 1220226601.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1220226601 = 11 ⋅110929691.

It is a cyclic number.

It is not a de Polignac number, because 1066220221 - 2¹ = 1066220219 is a prime.

It is a super-2 number, since 2×1066220221² = 2273651119338577682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1066220192 and 1066220201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1066220251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48464545 + ... + 48464566.

It is an arithmetic number, because the mean of its divisors is an integer number (290787336).

Almost surely, 2^1066220221 is an apocalyptic number.

1066220221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1066220221 is a deficient number, since it is larger than the sum of its proper divisors (96929123).

1066220221 is an equidigital number, since it uses as much as digits as its factorization.

1066220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96929122.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 1066220221 is about 32653.0277462902. The cubic root of 1066220221 is about 1021.6033418304.

Adding to 1066220221 its reverse (1220226601), we get a palindrome (2286446822).

The spelling of 1066220221 in words is "one billion, sixty-six million, two hundred twenty thousand, two hundred twenty-one".