1081991901812 has 6 divisors (see below), whose sum is σ = 1893485828178. Its totient is φ = 540995950904.

The previous prime is 1081991901751. The next prime is 1081991901827. The reversal of 1081991901812 is 2181091991801.

It can be written as a sum of positive squares in only one way, i.e., 589249675876 + 492742225936 = 767626^2 + 701956^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 135248987723 + ... + 135248987730.

It is an arithmetic number, because the mean of its divisors is an integer number (315580971363).

Almost surely, 2^{1081991901812} is an apocalyptic number.

It is an amenable number.

1081991901812 is a deficient number, since it is larger than the sum of its proper divisors (811493926366).

1081991901812 is a wasteful number, since it uses less digits than its factorization.

1081991901812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270497975457 (or 270497975455 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 50.

The spelling of 1081991901812 in words is "one trillion, eighty-one billion, nine hundred ninety-one million, nine hundred one thousand, eight hundred twelve".