1091851591679 has 4 divisors (see below), whose sum is σ = 1110357550920. Its totient is φ = 1073345632440.

The previous prime is 1091851591651. The next prime is 1091851591703. The reversal of 1091851591679 is 9761951581901.

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 1091851591679 - 2²⁰ = 1091850543103 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 (1091851591609) 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, 9252979532 + ... + 9252979649.

It is an arithmetic number, because the mean of its divisors is an integer number (277589387730).

Almost surely, 2^{1091851591679} is an apocalyptic number.

1091851591679 is a deficient number, since it is larger than the sum of its proper divisors (18505959241).

1091851591679 is an equidigital number, since it uses as much as digits as its factorization.

1091851591679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18505959240.

The product of its (nonzero) digits is 6123600, while the sum is 62.

The spelling of 1091851591679 in words is "one trillion, ninety-one billion, eight hundred fifty-one million, five hundred ninety-one thousand, six hundred seventy-nine".