7666221 has 8 divisors (see below), whose sum is σ = 10471104. Its totient is φ = 4986080.

The previous prime is 7666213. The next prime is 7666247. The reversal of 7666221 is 1226667.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7666221 - 2³ = 7666213 is a prime.

7666221 is a lucky number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7666261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31041 + ... + 31286.

It is an arithmetic number, because the mean of its divisors is an integer number (1308888).

Almost surely, 2^7666221 is an apocalyptic number.

It is an amenable number.

7666221 is a deficient number, since it is larger than the sum of its proper divisors (2804883).

7666221 is a wasteful number, since it uses less digits than its factorization.

7666221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62371.

The product of its digits is 6048, while the sum is 30.

The square root of 7666221 is about 2768.7941418603. The cubic root of 7666221 is about 197.1789024768.

It can be divided in two parts, 7666 and 221, that added together give a palindrome (7887).

The spelling of 7666221 in words is "seven million, six hundred sixty-six thousand, two hundred twenty-one".