131111505 has 72 divisors (see below), whose sum is σ = 267524712. Its totient is φ = 59222016.

The previous prime is 131111503. The next prime is 131111537. The reversal of 131111505 is 505111131.

It can be written as a sum of positive squares in 4 ways, for example, as 603729 + 130507776 = 777^2 + 11424^2 .

It is not a de Polignac number, because 131111505 - 2¹ = 131111503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131111501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 213579 + ... + 214191.

It is an arithmetic number, because the mean of its divisors is an integer number (3715621).

Almost surely, 2^131111505 is an apocalyptic number.

131111505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131111505 is an abundant number, since it is smaller than the sum of its proper divisors (136413207).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131111505 is a wasteful number, since it uses less digits than its factorization.

131111505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 75, while the sum is 18.

The square root of 131111505 is about 11450.3932246888. The cubic root of 131111505 is about 508.0193652588.

Adding to 131111505 its reverse (505111131), we get a palindrome (636222636).

The spelling of 131111505 in words is "one hundred thirty-one million, one hundred eleven thousand, five hundred five".