6541990784181 has 24 divisors (see below), whose sum is σ = 9556045274880. Its totient is φ = 4312175313600.

The previous prime is 6541990784177. The next prime is 6541990784201. The reversal of 6541990784181 is 1814870991456.

6541990784181 is a `hidden beast` number, since 6 + 54 + 19 + 90 + 78 + 418 + 1 = 666.

It is not a de Polignac number, because 6541990784181 - 2² = 6541990784177 is a prime.

It is a super-2 number, since 2×6541990784181² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6541990784171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26285916 + ... + 26533626.

It is an arithmetic number, because the mean of its divisors is an integer number (398168553120).

Almost surely, 2^{6541990784181} is an apocalyptic number.

It is an amenable number.

6541990784181 is a deficient number, since it is larger than the sum of its proper divisors (3014054490699).

6541990784181 is a wasteful number, since it uses less digits than its factorization.

6541990784181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280777 (or 280774 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 63.

The spelling of 6541990784181 in words is "six trillion, five hundred forty-one billion, nine hundred ninety million, seven hundred eighty-four thousand, one hundred eighty-one".