8181812139631 has 16 divisors (see below), whose sum is σ = 8938651790880. Its totient is φ = 7443724654080.

The previous prime is 8181812139619. The next prime is 8181812139653. The reversal of 8181812139631 is 1369312181818.

It is not a de Polignac number, because 8181812139631 - 2⁷ = 8181812139503 is a prime.

It is a super-2 number, since 2×8181812139631² (a number of 27 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 (8181812139661) 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 15 ways as a sum of consecutive naturals, for example, 10934305 + ... + 11658586.

It is an arithmetic number, because the mean of its divisors is an integer number (558665736930).

Almost surely, 2^{8181812139631} is an apocalyptic number.

8181812139631 is a deficient number, since it is larger than the sum of its proper divisors (756839651249).

8181812139631 is a wasteful number, since it uses less digits than its factorization.

8181812139631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22593306.

The product of its digits is 497664, while the sum is 52.

The spelling of 8181812139631 in words is "eight trillion, one hundred eighty-one billion, eight hundred twelve million, one hundred thirty-nine thousand, six hundred thirty-one".