2081556 has 36 divisors (see below), whose sum is σ = 5346432. Its totient is φ = 682704.

The previous prime is 2081549. The next prime is 2081561. The reversal of 2081556 is 6551802.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×2081556² = 8665750762272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1981 + ... + 2843.

It is an arithmetic number, because the mean of its divisors is an integer number (148512).

2^2081556 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 2081556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2673216).

2081556 is an abundant number, since it is smaller than the sum of its proper divisors (3264876).

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

2081556 is a wasteful number, since it uses less digits than its factorization.

2081556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940 (or 935 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 2081556 is about 1442.7598552774. The cubic root of 2081556 is about 127.6819087377.

It can be divided in two parts, 208 and 1556, that added together give a square (1764 = 42²).

The spelling of 2081556 in words is "two million, eighty-one thousand, five hundred fifty-six".