6881138639 has 2 divisors, whose sum is σ = 6881138640. Its totient is φ = 6881138638.

The previous prime is 6881138623. The next prime is 6881138653. The reversal of 6881138639 is 9368311886.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6881138639 - 2⁴ = 6881138623 is a prime.

It is a super-3 number, since 3×6881138639³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6881138839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3440569319 + 3440569320.

It is an arithmetic number, because the mean of its divisors is an integer number (3440569320).

Almost surely, 2^6881138639 is an apocalyptic number.

6881138639 is a deficient number, since it is larger than the sum of its proper divisors (1).

6881138639 is an equidigital number, since it uses as much as digits as its factorization.

6881138639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 53.

The square root of 6881138639 is about 82952.6288854066. The cubic root of 6881138639 is about 1902.0420002608.

The spelling of 6881138639 in words is "six billion, eight hundred eighty-one million, one hundred thirty-eight thousand, six hundred thirty-nine".