6181991816 has 128 divisors (see below), whose sum is σ = 15599001600. Its totient is φ = 2218164480.

The previous prime is 6181991771. The next prime is 6181991839.

6181991816 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5949425 + ... + 5950463.

It is an arithmetic number, because the mean of its divisors is an integer number (121867200).

Almost surely, 2^6181991816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6181991816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7799500800).

6181991816 is an abundant number, since it is smaller than the sum of its proper divisors (9417009784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6181991816 is a wasteful number, since it uses less digits than its factorization.

6181991816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819 (or 1815 counting only the distinct ones).

The product of its digits is 186624, while the sum is 50.

The square root of 6181991816 is about 78625.6435013412. The cubic root of 6181991816 is about 1835.3101873006.

The spelling of 6181991816 in words is "six billion, one hundred eighty-one million, nine hundred ninety-one thousand, eight hundred sixteen".