6645881139 has 8 divisors (see below), whose sum is σ = 8862370752. Its totient is φ = 4429989480.

The previous prime is 6645881117. The next prime is 6645881191. The reversal of 6645881139 is 9311885466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6645881139 - 2⁵ = 6645881107 is a prime.

It is a super-2 number, since 2×6645881139² = 88335472227431874642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6645881091 and 6645881100.

It is not an unprimeable number, because it can be changed into a prime (6645861139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122877 + ... + 168494.

It is an arithmetic number, because the mean of its divisors is an integer number (1107796344).

Almost surely, 2^6645881139 is an apocalyptic number.

6645881139 is a deficient number, since it is larger than the sum of its proper divisors (2216489613).

6645881139 is a wasteful number, since it uses less digits than its factorization.

6645881139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298977.

The product of its digits is 1244160, while the sum is 51.

The square root of 6645881139 is about 81522.2738826635. The cubic root of 6645881139 is about 1880.1140283749.

The spelling of 6645881139 in words is "six billion, six hundred forty-five million, eight hundred eighty-one thousand, one hundred thirty-nine".