1081991901811 has 4 divisors (see below), whose sum is σ = 1082036917000. Its totient is φ = 1081946886624.

The previous prime is 1081991901751. The next prime is 1081991901827. The reversal of 1081991901811 is 1181091991801.

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 1081991901811 - 2²⁹ = 1081455030899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1081991901511) 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, 22471521 + ... + 22519618.

It is an arithmetic number, because the mean of its divisors is an integer number (270509229250).

Almost surely, 2^{1081991901811} is an apocalyptic number.

1081991901811 is a deficient number, since it is larger than the sum of its proper divisors (45015189).

1081991901811 is an equidigital number, since it uses as much as digits as its factorization.

1081991901811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45015188.

The product of its (nonzero) digits is 46656, while the sum is 49.

The spelling of 1081991901811 in words is "one trillion, eighty-one billion, nine hundred ninety-one million, nine hundred one thousand, eight hundred eleven".