31581681121 has 8 divisors (see below), whose sum is σ = 31999383360. Its totient is φ = 31166700528.

The previous prime is 31581681107. The next prime is 31581681139. The reversal of 31581681121 is 12118618513.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31581681121 - 2¹⁹ = 31581156833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31581681101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 657046 + ... + 703471.

It is an arithmetic number, because the mean of its divisors is an integer number (3999922920).

Almost surely, 2^31581681121 is an apocalyptic number.

It is an amenable number.

31581681121 is a deficient number, since it is larger than the sum of its proper divisors (417702239).

31581681121 is a wasteful number, since it uses less digits than its factorization.

31581681121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360823.

The product of its digits is 11520, while the sum is 37.

The spelling of 31581681121 in words is "thirty-one billion, five hundred eighty-one million, six hundred eighty-one thousand, one hundred twenty-one".