3181993681 has 8 divisors (see below), whose sum is σ = 3230424864. Its totient is φ = 3133590240.

The previous prime is 3181993663. The next prime is 3181993693. The reversal of 3181993681 is 1863991813.

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 3181993681 - 2⁷ = 3181993553 is a prime.

It is a super-2 number, since 2×3181993681² = 20250167571847859522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3181993601) 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, 433266 + ... + 440548.

It is an arithmetic number, because the mean of its divisors is an integer number (403803108).

Almost surely, 2^3181993681 is an apocalyptic number.

It is an amenable number.

3181993681 is a deficient number, since it is larger than the sum of its proper divisors (48431183).

3181993681 is an equidigital number, since it uses as much as digits as its factorization.

3181993681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13871.

The product of its digits is 279936, while the sum is 49.

The square root of 3181993681 is about 56409.1630943059. The cubic root of 3181993681 is about 1470.8434052823.

The spelling of 3181993681 in words is "three billion, one hundred eighty-one million, nine hundred ninety-three thousand, six hundred eighty-one".