31946122981 has 4 divisors (see below), whose sum is σ = 32037659500. Its totient is φ = 31854586464.

The previous prime is 31946122939. The next prime is 31946122991. The reversal of 31946122981 is 18922164913.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18922164913 = 313 ⋅60454201.

It can be written as a sum of positive squares in 2 ways, for example, as 28747202500 + 3198920481 = 169550^2 + 56559^2 .

It is a cyclic number.

It is not a de Polignac number, because 31946122981 - 2¹³ = 31946114789 is a prime.

It is a super-2 number, since 2×31946122981² (a number of 22 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 (31946122991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45767736 + ... + 45768433.

It is an arithmetic number, because the mean of its divisors is an integer number (8009414875).

Almost surely, 2^31946122981 is an apocalyptic number.

It is an amenable number.

31946122981 is a deficient number, since it is larger than the sum of its proper divisors (91536519).

31946122981 is an equidigital number, since it uses as much as digits as its factorization.

31946122981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91536518.

The product of its digits is 186624, while the sum is 46.

The spelling of 31946122981 in words is "thirty-one billion, nine hundred forty-six million, one hundred twenty-two thousand, nine hundred eighty-one".