1691081811144 has 512 divisors, whose sum is σ = 5294612736000. Its totient is φ = 501986833920.

The previous prime is 1691081811143. The next prime is 1691081811163. The reversal of 1691081811144 is 4411181801961.

It is a self number, because there is not a number n which added to its sum of digits gives 1691081811144.

It is not an unprimeable number, because it can be changed into a prime (1691081811143) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4035994567 + ... + 4035994985.

It is an arithmetic number, because the mean of its divisors is an integer number (10341040500).

Almost surely, 2^{1691081811144} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1691081811144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2647306368000).

1691081811144 is an abundant number, since it is smaller than the sum of its proper divisors (3603530924856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1691081811144 is a wasteful number, since it uses less digits than its factorization.

1691081811144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 45.

The spelling of 1691081811144 in words is "one trillion, six hundred ninety-one billion, eighty-one million, eight hundred eleven thousand, one hundred forty-four".