31881220131 has 8 divisors (see below), whose sum is σ = 42517558864. Its totient is φ = 21249514080.

The previous prime is 31881220109. The next prime is 31881220141. The reversal of 31881220131 is 13102218813.

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

It is not a de Polignac number, because 31881220131 - 2⁶ = 31881220067 is a prime.

It is a super-2 number, since 2×31881220131² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31881220141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1142080 + ... + 1169661.

It is an arithmetic number, because the mean of its divisors is an integer number (5314694858).

Almost surely, 2^31881220131 is an apocalyptic number.

31881220131 is a deficient number, since it is larger than the sum of its proper divisors (10636338733).

31881220131 is a wasteful number, since it uses less digits than its factorization.

31881220131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2316341.

The product of its (nonzero) digits is 2304, while the sum is 30.

Adding to 31881220131 its reverse (13102218813), we get a palindrome (44983438944).

The spelling of 31881220131 in words is "thirty-one billion, eight hundred eighty-one million, two hundred twenty thousand, one hundred thirty-one".