1820581056 has 224 divisors, whose sum is σ = 6267663360. Its totient is φ = 507340800.

The previous prime is 1820581043. The next prime is 1820581093. The reversal of 1820581056 is 6501850281.

1820581056 is a `hidden beast` number, since 1 + 8 + 20 + 581 + 0 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1820581056.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 494101 + ... + 497771.

It is an arithmetic number, because the mean of its divisors is an integer number (27980640).

Almost surely, 2^1820581056 is an apocalyptic number.

1820581056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1820581056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3133831680).

1820581056 is an abundant number, since it is smaller than the sum of its proper divisors (4447082304).

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

1820581056 is a wasteful number, since it uses less digits than its factorization.

1820581056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3740 (or 3724 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The square root of 1820581056 is about 42668.2675533001. The cubic root of 1820581056 is about 1221.0590678281.

The spelling of 1820581056 in words is "one billion, eight hundred twenty million, five hundred eighty-one thousand, fifty-six".