1231540543305 has 32 divisors (see below), whose sum is σ = 2220242123520. Its totient is φ = 647570609280.

The previous prime is 1231540543267. The next prime is 1231540543333. The reversal of 1231540543305 is 5033450451321.

1231540543305 is a `hidden beast` number, since 1 + 2 + 31 + 54 + 0 + 543 + 30 + 5 = 666.

It is not a de Polignac number, because 1231540543305 - 2¹² = 1231540539209 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231540543305.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 64233532 + ... + 64252701.

It is an arithmetic number, because the mean of its divisors is an integer number (69382566360).

Almost surely, 2^{1231540543305} is an apocalyptic number.

1231540543305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231540543305 is a deficient number, since it is larger than the sum of its proper divisors (988701580215).

1231540543305 is a wasteful number, since it uses less digits than its factorization.

1231540543305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128486318 (or 128486312 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

Adding to 1231540543305 its reverse (5033450451321), we get a palindrome (6264990994626).

The spelling of 1231540543305 in words is "one trillion, two hundred thirty-one billion, five hundred forty million, five hundred forty-three thousand, three hundred five".