6991839555 has 16 divisors (see below), whose sum is σ = 11312641440. Its totient is φ = 3687081728.

The previous prime is 6991839539. The next prime is 6991839557. The reversal of 6991839555 is 5559381996.

It is a cyclic number.

It is not a de Polignac number, because 6991839555 - 2⁴ = 6991839539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6991839557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2617332 + ... + 2620001.

It is an arithmetic number, because the mean of its divisors is an integer number (707040090).

Almost surely, 2^6991839555 is an apocalyptic number.

6991839555 is a deficient number, since it is larger than the sum of its proper divisors (4320801885).

6991839555 is a wasteful number, since it uses less digits than its factorization.

6991839555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5237430.

The product of its digits is 13122000, while the sum is 60.

The square root of 6991839555 is about 83617.2204453126. The cubic root of 6991839555 is about 1912.1875427861.

The spelling of 6991839555 in words is "six billion, nine hundred ninety-one million, eight hundred thirty-nine thousand, five hundred fifty-five".