1231451135505 has 64 divisors (see below), whose sum is σ = 2231064000000. Its totient is φ = 644234363136.

The previous prime is 1231451135471. The next prime is 1231451135531. The reversal of 1231451135505 is 5055311541321.

1231451135505 is a `hidden beast` number, since 1 + 2 + 3 + 14 + 5 + 1 + 135 + 505 = 666.

It is not a de Polignac number, because 1231451135505 - 2²¹ = 1231449038353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1231451135505.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 35750631 + ... + 35785059.

It is an arithmetic number, because the mean of its divisors is an integer number (34860375000).

Almost surely, 2^{1231451135505} is an apocalyptic number.

1231451135505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231451135505 is a deficient number, since it is larger than the sum of its proper divisors (999612864495).

1231451135505 is a wasteful number, since it uses less digits than its factorization.

1231451135505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39495 (or 39489 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

Adding to 1231451135505 its reverse (5055311541321), we get a palindrome (6286762676826).

The spelling of 1231451135505 in words is "one trillion, two hundred thirty-one billion, four hundred fifty-one million, one hundred thirty-five thousand, five hundred five".