1261364867543 has 4 divisors (see below), whose sum is σ = 1376034400968. Its totient is φ = 1146695334120.

The previous prime is 1261364867491. The next prime is 1261364867561. The reversal of 1261364867543 is 3457684631621.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261364867543 - 2³⁰ = 1260291125719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261364867843) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 57334766696 + ... + 57334766717.

It is an arithmetic number, because the mean of its divisors is an integer number (344008600242).

Almost surely, 2^{1261364867543} is an apocalyptic number.

1261364867543 is a deficient number, since it is larger than the sum of its proper divisors (114669533425).

1261364867543 is a wasteful number, since it uses less digits than its factorization.

1261364867543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114669533424.

The product of its digits is 17418240, while the sum is 56.

The spelling of 1261364867543 in words is "one trillion, two hundred sixty-one billion, three hundred sixty-four million, eight hundred sixty-seven thousand, five hundred forty-three".