6555938553981 has 24 divisors (see below), whose sum is σ = 10035162479160. Its totient is φ = 4116989721600.

The previous prime is 6555938553949. The next prime is 6555938554111. The reversal of 6555938553981 is 1893558395556.

6555938553981 is a `hidden beast` number, since 6 + 5 + 5 + 5 + 9 + 3 + 8 + 5 + 539 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 45740376900 + 6510198177081 = 213870^2 + 2551509^2 .

It is not a de Polignac number, because 6555938553981 - 2⁵ = 6555938553949 is a prime.

It is a super-2 number, since 2×6555938553981² (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 (6555938553911) 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, 306312940 + ... + 306334341.

It is an arithmetic number, because the mean of its divisors is an integer number (418131769965).

Almost surely, 2^{6555938553981} is an apocalyptic number.

It is an amenable number.

6555938553981 is a deficient number, since it is larger than the sum of its proper divisors (3479223925179).

6555938553981 is a wasteful number, since it uses less digits than its factorization.

6555938553981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612647357 (or 612647354 counting only the distinct ones).

The product of its digits is 874800000, while the sum is 72.

The spelling of 6555938553981 in words is "six trillion, five hundred fifty-five billion, nine hundred thirty-eight million, five hundred fifty-three thousand, nine hundred eighty-one".