671562221121 has 81 divisors (see below), whose sum is σ = 1126168964193. Its totient is φ = 385290948240.

The previous prime is 671562221089. The next prime is 671562221147. The reversal of 671562221121 is 121122265176.

The square root of 671562221121 is 819489.

It is a perfect power (a square), and thus also a powerful number.

671562221121 is a `hidden beast` number, since 6 + 7 + 1 + 5 + 622 + 2 + 1 + 1 + 21 = 666.

It is not a de Polignac number, because 671562221121 - 2⁵ = 671562221089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (671562221171) 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 80 ways as a sum of consecutive naturals, for example, 513818950 + ... + 513820256.

Almost surely, 2^671562221121 is an apocalyptic number.

671562221121 is the 819489-th square number.

671562221121 is the 409745-th centered octagonal number.

It is an amenable number.

671562221121 is a deficient number, since it is larger than the sum of its proper divisors (454606743072).

671562221121 is a wasteful number, since it uses less digits than its factorization.

671562221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2680 (or 1340 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

Multiplying 671562221121 by its sum of digits (36), we get a square (24176239960356 = 4916934²).

Adding to 671562221121 its reverse (121122265176), we get a palindrome (792684486297).

The spelling of 671562221121 in words is "six hundred seventy-one billion, five hundred sixty-two million, two hundred twenty-one thousand, one hundred twenty-one".