6981889861 has 2 divisors, whose sum is σ = 6981889862. Its totient is φ = 6981889860.

The previous prime is 6981889819. The next prime is 6981889879. The reversal of 6981889861 is 1689881896.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6053773636 + 928116225 = 77806^2 + 30465^2 .

It is a cyclic number.

It is not a de Polignac number, because 6981889861 - 2⁹ = 6981889349 is a prime.

It is a super-2 number, since 2×6981889861² = 97493572062269198642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6981889793 and 6981889802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6981889561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3490944930 + 3490944931.

It is an arithmetic number, because the mean of its divisors is an integer number (3490944931).

Almost surely, 2^6981889861 is an apocalyptic number.

It is an amenable number.

6981889861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6981889861 is an equidigital number, since it uses as much as digits as its factorization.

6981889861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11943936, while the sum is 64.

The square root of 6981889861 is about 83557.7037800824. The cubic root of 6981889861 is about 1911.2800699765.

The spelling of 6981889861 in words is "six billion, nine hundred eighty-one million, eight hundred eighty-nine thousand, eight hundred sixty-one".