8180664221 has 4 divisors (see below), whose sum is σ = 8401763292. Its totient is φ = 7959565152.

The previous prime is 8180664211. The next prime is 8180664241. The reversal of 8180664221 is 1224660818.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4514361721 + 3666302500 = 67189^2 + 60550^2 .

It is a cyclic number.

It is not a de Polignac number, because 8180664221 - 2⁶ = 8180664157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8180664211) 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, 110549480 + ... + 110549553.

It is an arithmetic number, because the mean of its divisors is an integer number (2100440823).

Almost surely, 2^8180664221 is an apocalyptic number.

It is an amenable number.

8180664221 is a deficient number, since it is larger than the sum of its proper divisors (221099071).

8180664221 is a wasteful number, since it uses less digits than its factorization.

8180664221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221099070.

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 8180664221 is about 90447.0243899710. The cubic root of 8180664221 is about 2014.9434207586.

The spelling of 8180664221 in words is "eight billion, one hundred eighty million, six hundred sixty-four thousand, two hundred twenty-one".