6888899981 has 2 divisors, whose sum is σ = 6888899982. Its totient is φ = 6888899980.

The previous prime is 6888899971. The next prime is 6888899999. The reversal of 6888899981 is 1899988886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6341573956 + 547326025 = 79634^2 + 23395^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6888899981 is a prime.

It is a super-2 number, since 2×6888899981² = 94913885896443600722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6888899899 and 6888899908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6888899921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3444449990 + 3444449991.

It is an arithmetic number, because the mean of its divisors is an integer number (3444449991).

Almost surely, 2^6888899981 is an apocalyptic number.

It is an amenable number.

6888899981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6888899981 is an equidigital number, since it uses as much as digits as its factorization.

6888899981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 143327232, while the sum is 74.

The square root of 6888899981 is about 82999.3974737166. The cubic root of 6888899981 is about 1902.7568456988.

The spelling of 6888899981 in words is "six billion, eight hundred eighty-eight million, eight hundred ninety-nine thousand, nine hundred eighty-one".