31122136305 has 72 divisors (see below), whose sum is σ = 60326825832. Its totient is φ = 15321457152.

The previous prime is 31122136301. The next prime is 31122136327. The reversal of 31122136305 is 50363122113.

31122136305 is a `hidden beast` number, since 3 + 1 + 1 + 2 + 21 + 3 + 630 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 170067681 + 30952068624 = 13041^2 + 175932^2 .

It is not a de Polignac number, because 31122136305 - 2² = 31122136301 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31122136301) 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 71 ways as a sum of consecutive naturals, for example, 389977 + ... + 462953.

It is an arithmetic number, because the mean of its divisors is an integer number (837872581).

Almost surely, 2^31122136305 is an apocalyptic number.

It is an amenable number.

31122136305 is a deficient number, since it is larger than the sum of its proper divisors (29204689527).

31122136305 is an frugal number, since it uses more digits than its factorization.

31122136305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73019 (or 72998 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

Adding to 31122136305 its reverse (50363122113), we get a palindrome (81485258418).

The spelling of 31122136305 in words is "thirty-one billion, one hundred twenty-two million, one hundred thirty-six thousand, three hundred five".