31931606173 has 2 divisors, whose sum is σ = 31931606174. Its totient is φ = 31931606172.

The previous prime is 31931606153. The next prime is 31931606227. The reversal of 31931606173 is 37160613913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31674388729 + 257217444 = 177973^2 + 16038^2 .

It is a cyclic number.

It is not a de Polignac number, because 31931606173 - 2⁹ = 31931605661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31931606153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15965803086 + 15965803087.

It is an arithmetic number, because the mean of its divisors is an integer number (15965803087).

Almost surely, 2^31931606173 is an apocalyptic number.

It is an amenable number.

31931606173 is a deficient number, since it is larger than the sum of its proper divisors (1).

31931606173 is an equidigital number, since it uses as much as digits as its factorization.

31931606173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 40.

The spelling of 31931606173 in words is "thirty-one billion, nine hundred thirty-one million, six hundred six thousand, one hundred seventy-three".