31505305105 has 4 divisors (see below), whose sum is σ = 37806366132. Its totient is φ = 25204244080.

The previous prime is 31505305103. The next prime is 31505305109. The reversal of 31505305105 is 50150350513.

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 17028162064 + 14477143041 = 130492^2 + 120321^2 .

It is not a de Polignac number, because 31505305105 - 2¹ = 31505305103 is a prime.

It is a super-2 number, since 2×31505305105² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31505305103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3150530506 + ... + 3150530515.

It is an arithmetic number, because the mean of its divisors is an integer number (9451591533).

Almost surely, 2^31505305105 is an apocalyptic number.

It is an amenable number.

31505305105 is a deficient number, since it is larger than the sum of its proper divisors (6301061027).

31505305105 is an equidigital number, since it uses as much as digits as its factorization.

31505305105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6301061026.

The product of its (nonzero) digits is 5625, while the sum is 28.

Adding to 31505305105 its reverse (50150350513), we get a palindrome (81655655618).

It can be divided in two parts, 31505 and 305105, that added together give a triangular number (336610 = T₈₂₀).

The spelling of 31505305105 in words is "thirty-one billion, five hundred five million, three hundred five thousand, one hundred five".