1131326405865 has 40 divisors (see below), whose sum is σ = 2045954385288. Its totient is φ = 598034465280.

The previous prime is 1131326405861. The next prime is 1131326405917. The reversal of 1131326405865 is 5685046231311.

1131326405865 is a `hidden beast` number, since 1 + 1 + 3 + 1 + 3 + 2 + 64 + 0 + 586 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 66574836441 + 1064751569424 = 258021^2 + 1031868^2 .

It is not a de Polignac number, because 1131326405865 - 2² = 1131326405861 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1131326405865.

It is not an unprimeable number, because it can be changed into a prime (1131326405861) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 12314406 + ... + 12405935.

Almost surely, 2^{1131326405865} is an apocalyptic number.

1131326405865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1131326405865 is a deficient number, since it is larger than the sum of its proper divisors (914627979423).

1131326405865 is a wasteful number, since it uses less digits than its factorization.

1131326405865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24720471 (or 24720462 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 1131326405865 in words is "one trillion, one hundred thirty-one billion, three hundred twenty-six million, four hundred five thousand, eight hundred sixty-five".