11531978684143 has 4 divisors (see below), whose sum is σ = 11586632611768. Its totient is φ = 11477324756520.

The previous prime is 11531978684101. The next prime is 11531978684159. The reversal of 11531978684143 is 34148687913511.

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 11531978684143 - 2¹³ = 11531978675951 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 (11531978684173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27326963496 + ... + 27326963917.

It is an arithmetic number, because the mean of its divisors is an integer number (2896658152942).

Almost surely, 2^{11531978684143} is an apocalyptic number.

11531978684143 is a deficient number, since it is larger than the sum of its proper divisors (54653927625).

11531978684143 is an equidigital number, since it uses as much as digits as its factorization.

11531978684143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54653927624.

The product of its digits is 17418240, while the sum is 61.

The spelling of 11531978684143 in words is "eleven trillion, five hundred thirty-one billion, nine hundred seventy-eight million, six hundred eighty-four thousand, one hundred forty-three".