6181991022321 has 9 divisors (see below), whose sum is σ = 8929553362041. Its totient is φ = 4121322375492.

The previous prime is 6181991022287. The next prime is 6181991022323. The reversal of 6181991022321 is 1232201991816.

The square root of 6181991022321 is 2486361.

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

6181991022321 is a `hidden beast` number, since 61 + 81 + 99 + 102 + 2 + 321 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is a de Polignac number, because none of the positive numbers 2^k-6181991022321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6181991022323) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7044690 + ... + 7873476.

Almost surely, 2^{6181991022321} is an apocalyptic number.

6181991022321 is the 2486361-st square number.

6181991022321 is the 1243181-st centered octagonal number.

It is an amenable number.

6181991022321 is a deficient number, since it is larger than the sum of its proper divisors (2747562339720).

6181991022321 is an frugal number, since it uses more digits than its factorization.

6181991022321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1657580 (or 828790 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 6181991022321 in words is "six trillion, one hundred eighty-one billion, nine hundred ninety-one million, twenty-two thousand, three hundred twenty-one".