2105808555690 has 576 divisors, whose sum is σ = 6701593377024. Its totient is φ = 474338737152.

The previous prime is 2105808555569. The next prime is 2105808555709. The reversal of 2105808555690 is 965558085012.

2105808555690 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 8 + 0 + 85 + 556 + 9 + 0 = 666.

It is a super-2 number, since 2×2105808555690² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 2724202144 + ... + 2724202916.

It is an arithmetic number, because the mean of its divisors is an integer number (11634710724).

Almost surely, 2^{2105808555690} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2105808555690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3350796688512).

2105808555690 is an abundant number, since it is smaller than the sum of its proper divisors (4595784821334).

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

2105808555690 is a wasteful number, since it uses less digits than its factorization.

2105808555690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113 (or 1094 counting only the distinct ones).

The product of its (nonzero) digits is 4320000, while the sum is 54.

The spelling of 2105808555690 in words is "two trillion, one hundred five billion, eight hundred eight million, five hundred fifty-five thousand, six hundred ninety".