6621221266 has 16 divisors (see below), whose sum is σ = 10996440480. Its totient is φ = 2964725280.

The previous prime is 6621221263. The next prime is 6621221267.

6621221266 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (6621221263) 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, 2244531 + ... + 2247478.

It is an arithmetic number, because the mean of its divisors is an integer number (687277530).

Almost surely, 2^6621221266 is an apocalyptic number.

6621221266 is a deficient number, since it is larger than the sum of its proper divisors (4375219214).

6621221266 is a wasteful number, since it uses less digits than its factorization.

6621221266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4492089.

The product of its digits is 20736, while the sum is 34.

The square root of 6621221266 is about 81370.8870911458. The cubic root of 6621221266 is about 1877.7857273198.

It can be divided in two parts, 66212 and 21266, that added together give a palindrome (87478).

The spelling of 6621221266 in words is "six billion, six hundred twenty-one million, two hundred twenty-one thousand, two hundred sixty-six".