31405848181 has 2 divisors, whose sum is σ = 31405848182. Its totient is φ = 31405848180.

The previous prime is 31405848143. The next prime is 31405848197. The reversal of 31405848181 is 18184850413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26362717956 + 5043130225 = 162366^2 + 71015^2 .

It is an emirp because it is prime and its reverse (18184850413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31405848181 - 2¹³ = 31405839989 is a prime.

It is a super-2 number, since 2×31405848181² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31405848281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15702924090 + 15702924091.

It is an arithmetic number, because the mean of its divisors is an integer number (15702924091).

Almost surely, 2^31405848181 is an apocalyptic number.

It is an amenable number.

31405848181 is a deficient number, since it is larger than the sum of its proper divisors (1).

31405848181 is an equidigital number, since it uses as much as digits as its factorization.

31405848181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122880, while the sum is 43.

The spelling of 31405848181 in words is "thirty-one billion, four hundred five million, eight hundred forty-eight thousand, one hundred eighty-one".