6115881781 has 2 divisors, whose sum is σ = 6115881782. Its totient is φ = 6115881780.

The previous prime is 6115881757. The next prime is 6115881799. The reversal of 6115881781 is 1871885116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4053359556 + 2062522225 = 63666^2 + 45415^2 .

It is a cyclic number.

It is not a de Polignac number, because 6115881781 - 2⁹ = 6115881269 is a prime.

It is a super-2 number, since 2×6115881781² = 74808019918335463922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6115881731) 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, 3057940890 + 3057940891.

It is an arithmetic number, because the mean of its divisors is an integer number (3057940891).

Almost surely, 2^6115881781 is an apocalyptic number.

It is an amenable number.

6115881781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6115881781 is an equidigital number, since it uses as much as digits as its factorization.

6115881781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107520, while the sum is 46.

The square root of 6115881781 is about 78204.1033514227. The cubic root of 6115881781 is about 1828.7444761834.

The spelling of 6115881781 in words is "six billion, one hundred fifteen million, eight hundred eighty-one thousand, seven hundred eighty-one".