6655101221 has 16 divisors (see below), whose sum is σ = 7197586560. Its totient is φ = 6134546880.

The previous prime is 6655101217. The next prime is 6655101287. The reversal of 6655101221 is 1221015566.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 6655101221 - 2² = 6655101217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6655101821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 351626 + ... + 370068.

It is an arithmetic number, because the mean of its divisors is an integer number (449849160).

Almost surely, 2^6655101221 is an apocalyptic number.

It is an amenable number.

6655101221 is a deficient number, since it is larger than the sum of its proper divisors (542485339).

6655101221 is a wasteful number, since it uses less digits than its factorization.

6655101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19036.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 6655101221 is about 81578.8037482777. The cubic root of 6655101221 is about 1880.9830776858.

Adding to 6655101221 its reverse (1221015566), we get a palindrome (7876116787).

The spelling of 6655101221 in words is "six billion, six hundred fifty-five million, one hundred one thousand, two hundred twenty-one".