1231560657791 has 8 divisors (see below), whose sum is σ = 1298056731120. Its totient is φ = 1165232293632.

The previous prime is 1231560657757. The next prime is 1231560657793. The reversal of 1231560657791 is 1977560651321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1231560657791 - 2¹⁸ = 1231560395647 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 (1231560657793) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41912210 + ... + 41941583.

It is an arithmetic number, because the mean of its divisors is an integer number (162257091390).

Almost surely, 2^{1231560657791} is an apocalyptic number.

1231560657791 is a deficient number, since it is larger than the sum of its proper divisors (66496073329).

1231560657791 is an equidigital number, since it uses as much as digits as its factorization.

1231560657791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83854585.

The product of its (nonzero) digits is 2381400, while the sum is 53.

The spelling of 1231560657791 in words is "one trillion, two hundred thirty-one billion, five hundred sixty million, six hundred fifty-seven thousand, seven hundred ninety-one".