31423432181 has 2 divisors, whose sum is σ = 31423432182. Its totient is φ = 31423432180.

The previous prime is 31423432171. The next prime is 31423432211. The reversal of 31423432181 is 18123432413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31414372081 + 9060100 = 177241^2 + 3010^2 .

It is an emirp because it is prime and its reverse (18123432413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31423432181 - 2¹⁰ = 31423431157 is a prime.

It is a super-2 number, since 2×31423432181² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31423432141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15711716090 + 15711716091.

It is an arithmetic number, because the mean of its divisors is an integer number (15711716091).

Almost surely, 2^31423432181 is an apocalyptic number.

It is an amenable number.

31423432181 is a deficient number, since it is larger than the sum of its proper divisors (1).

31423432181 is an equidigital number, since it uses as much as digits as its factorization.

31423432181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 32.

Adding to 31423432181 its reverse (18123432413), we get a palindrome (49546864594).

The spelling of 31423432181 in words is "thirty-one billion, four hundred twenty-three million, four hundred thirty-two thousand, one hundred eighty-one".