1131471181861 has 4 divisors (see below), whose sum is σ = 1131506593324. Its totient is φ = 1131435770400.

The previous prime is 1131471181777. The next prime is 1131471181891. The reversal of 1131471181861 is 1681811741311.

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

It can be written as a sum of positive squares in 2 ways, for example, as 99347257636 + 1032123924225 = 315194^2 + 1015935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1131471181861 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 (1131471181891) 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, 17657760 + ... + 17721721.

It is an arithmetic number, because the mean of its divisors is an integer number (282876648331).

Almost surely, 2^{1131471181861} is an apocalyptic number.

It is an amenable number.

1131471181861 is a deficient number, since it is larger than the sum of its proper divisors (35411463).

1131471181861 is an equidigital number, since it uses as much as digits as its factorization.

1131471181861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35411462.

The product of its digits is 32256, while the sum is 43.

The spelling of 1131471181861 in words is "one trillion, one hundred thirty-one billion, four hundred seventy-one million, one hundred eighty-one thousand, eight hundred sixty-one".