31001111161 has 2 divisors, whose sum is σ = 31001111162. Its totient is φ = 31001111160.

The previous prime is 31001111147. The next prime is 31001111173. The reversal of 31001111161 is 16111110013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18294185536 + 12706925625 = 135256^2 + 112725^2 .

It is an emirp because it is prime and its reverse (16111110013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31001111161 - 2²⁵ = 30967556729 is a prime.

It is a super-2 number, since 2×31001111161² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31001111111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500555580 + 15500555581.

It is an arithmetic number, because the mean of its divisors is an integer number (15500555581).

Almost surely, 2^31001111161 is an apocalyptic number.

It is an amenable number.

31001111161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31001111161 is an equidigital number, since it uses as much as digits as its factorization.

31001111161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 16.

Adding to 31001111161 its reverse (16111110013), we get a palindrome (47112221174).

The spelling of 31001111161 in words is "thirty-one billion, one million, one hundred eleven thousand, one hundred sixty-one".