6181920581 has 2 divisors, whose sum is σ = 6181920582. Its totient is φ = 6181920580.

The previous prime is 6181920529. The next prime is 6181920587. The reversal of 6181920581 is 1850291816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3218860225 + 2963060356 = 56735^2 + 54434^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6181920581 is a prime.

It is a super-2 number, since 2×6181920581² = 76432284139582755122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6181920587) 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 as a sum of consecutive naturals, namely, 3090960290 + 3090960291.

It is an arithmetic number, because the mean of its divisors is an integer number (3090960291).

Almost surely, 2^6181920581 is an apocalyptic number.

It is an amenable number.

6181920581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6181920581 is an equidigital number, since it uses as much as digits as its factorization.

6181920581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 41.

The square root of 6181920581 is about 78625.1904989743. The cubic root of 6181920581 is about 1835.3031378562.

The spelling of 6181920581 in words is "six billion, one hundred eighty-one million, nine hundred twenty thousand, five hundred eighty-one".