31111151161 has 4 divisors (see below), whose sum is σ = 31131185652. Its totient is φ = 31091116672.

The previous prime is 31111151129. The next prime is 31111151167. The reversal of 31111151161 is 16115111113.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5562325561 + 25548825600 = 74581^2 + 159840^2 .

It is a cyclic number.

It is not a de Polignac number, because 31111151161 - 2⁵ = 31111151129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31111151167) 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 in 3 ways as a sum of consecutive naturals, for example, 10014916 + ... + 10018021.

It is an arithmetic number, because the mean of its divisors is an integer number (7782796413).

Almost surely, 2^31111151161 is an apocalyptic number.

It is an amenable number.

31111151161 is a deficient number, since it is larger than the sum of its proper divisors (20034491).

31111151161 is a wasteful number, since it uses less digits than its factorization.

31111151161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20034490.

The product of its digits is 90, while the sum is 22.

Adding to 31111151161 its reverse (16115111113), we get a palindrome (47226262274).

The spelling of 31111151161 in words is "thirty-one billion, one hundred eleven million, one hundred fifty-one thousand, one hundred sixty-one".