839840399989 has 2 divisors, whose sum is σ = 839840399990. Its totient is φ = 839840399988.

The previous prime is 839840399971. The next prime is 839840400001. The reversal of 839840399989 is 989993048938.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 700304532964 + 139535867025 = 836842^2 + 373545^2 .

It is a cyclic number.

It is not a de Polignac number, because 839840399989 - 2⁷ = 839840399861 is a prime.

It is a super-2 number, since 2×839840399989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (839840399929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 419920199994 + 419920199995.

It is an arithmetic number, because the mean of its divisors is an integer number (419920199995).

Almost surely, 2^839840399989 is an apocalyptic number.

It is an amenable number.

839840399989 is a deficient number, since it is larger than the sum of its proper divisors (1).

839840399989 is an equidigital number, since it uses as much as digits as its factorization.

839840399989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088391168, while the sum is 79.

The spelling of 839840399989 in words is "eight hundred thirty-nine billion, eight hundred forty million, three hundred ninety-nine thousand, nine hundred eighty-nine".