2081549778 has 64 divisors (see below), whose sum is σ = 5228402688. Its totient is φ = 536699520.

The previous prime is 2081549761. The next prime is 2081549797. The reversal of 2081549778 is 8779451802.

It is a self number, because there is not a number n which added to its sum of digits gives 2081549778.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46851 + ... + 79737.

It is an arithmetic number, because the mean of its divisors is an integer number (81693792).

Almost surely, 2^2081549778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2081549778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2614201344).

2081549778 is an abundant number, since it is smaller than the sum of its proper divisors (3146852910).

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

2081549778 is a wasteful number, since it uses less digits than its factorization.

2081549778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33047.

The product of its (nonzero) digits is 1128960, while the sum is 51.

The square root of 2081549778 is about 45624.0044055758. The cubic root of 2081549778 is about 1276.8178151919.

The spelling of 2081549778 in words is "two billion, eighty-one million, five hundred forty-nine thousand, seven hundred seventy-eight".