66122221 has 4 divisors (see below), whose sum is σ = 72133344. Its totient is φ = 60111100.

The previous prime is 66122213. The next prime is 66122239. The reversal of 66122221 is 12222166.

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.

It is a cyclic number.

It is not a de Polignac number, because 66122221 - 2³ = 66122213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66122192 and 66122201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66122321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3005545 + ... + 3005566.

It is an arithmetic number, because the mean of its divisors is an integer number (18033336).

Almost surely, 2^66122221 is an apocalyptic number.

It is an amenable number.

66122221 is a deficient number, since it is larger than the sum of its proper divisors (6011123).

66122221 is a wasteful number, since it uses less digits than its factorization.

66122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6011122.

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

The square root of 66122221 is about 8131.5571079591. The cubic root of 66122221 is about 404.3733050023.

Adding to 66122221 its reverse (12222166), we get a palindrome (78344387).

The spelling of 66122221 in words is "sixty-six million, one hundred twenty-two thousand, two hundred twenty-one".