1231161265642 has 16 divisors (see below), whose sum is σ = 2302431458112. Its totient is φ = 479673220320.

The previous prime is 1231161265613. The next prime is 1231161265667. The reversal of 1231161265642 is 2465621611321.

It is a super-2 number, since 2×1231161265642² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1231161265595 and 1231161265604.

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 7 ways as a sum of consecutive naturals, for example, 3997276683 + ... + 3997276990.

It is an arithmetic number, because the mean of its divisors is an integer number (143901966132).

Almost surely, 2^{1231161265642} is an apocalyptic number.

1231161265642 is a deficient number, since it is larger than the sum of its proper divisors (1071270192470).

1231161265642 is a wasteful number, since it uses less digits than its factorization.

1231161265642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7994553693.

The product of its digits is 103680, while the sum is 40.

Adding to 1231161265642 its reverse (2465621611321), we get a palindrome (3696782876963).

The spelling of 1231161265642 in words is "one trillion, two hundred thirty-one billion, one hundred sixty-one million, two hundred sixty-five thousand, six hundred forty-two".