1866056987808 has 216 divisors, whose sum is σ = 5747986727028. Its totient is φ = 570840956928.

The previous prime is 1866056987761. The next prime is 1866056987827. The reversal of 1866056987808 is 8087896506681.

1866056987808 is a `hidden beast` number, since 1 + 8 + 6 + 605 + 6 + 9 + 8 + 7 + 8 + 0 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1669336352784 + 196720635024 = 1292028^2 + 443532^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1161204541 + ... + 1161206147.

Almost surely, 2^{1866056987808} is an apocalyptic number.

1866056987808 is a gapful number since it is divisible by the number (18) 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 1866056987808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2873993363514).

1866056987808 is an abundant number, since it is smaller than the sum of its proper divisors (3881929739220).

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

1866056987808 is a wasteful number, since it uses less digits than its factorization.

1866056987808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3436 (or 1818 counting only the distinct ones).

The product of its (nonzero) digits is 278691840, while the sum is 72.

The spelling of 1866056987808 in words is "one trillion, eight hundred sixty-six billion, fifty-six million, nine hundred eighty-seven thousand, eight hundred eight".