6991551659853 has 12 divisors (see below), whose sum is σ = 10098983737180. Its totient is φ = 4660999462656.

The previous prime is 6991551659839. The next prime is 6991551659909. The reversal of 6991551659853 is 3589561551996.

It is a happy number.

6991551659853 is a `hidden beast` number, since 6 + 9 + 9 + 1 + 5 + 516 + 59 + 8 + 53 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6804600924969 + 186950734884 = 2608563^2 + 432378^2 .

It is not a de Polignac number, because 6991551659853 - 2¹⁴ = 6991551643469 is a prime.

It is a super-2 number, since 2×6991551659853² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991556659853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1618468 + ... + 4074621.

Almost surely, 2^{6991551659853} is an apocalyptic number.

It is an amenable number.

6991551659853 is a deficient number, since it is larger than the sum of its proper divisors (3107432077327).

6991551659853 is a wasteful number, since it uses less digits than its factorization.

6991551659853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5829548 (or 5829545 counting only the distinct ones).

The product of its digits is 393660000, while the sum is 72.

The spelling of 6991551659853 in words is "six trillion, nine hundred ninety-one billion, five hundred fifty-one million, six hundred fifty-nine thousand, eight hundred fifty-three".