1866981505536 has 320 divisors, whose sum is σ = 6519628431360. Its totient is φ = 516215255040.

The previous prime is 1866981505531. The next prime is 1866981505547. The reversal of 1866981505536 is 6355051896681.

1866981505536 is a `hidden beast` number, since 1 + 8 + 6 + 6 + 98 + 1 + 5 + 0 + 5 + 536 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (1866981505531) by changing a digit.

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, 2688625 + ... + 3310991.

It is an arithmetic number, because the mean of its divisors is an integer number (20373838848).

Almost surely, 2^{1866981505536} is an apocalyptic number.

1866981505536 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 1866981505536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3259814215680).

1866981505536 is an abundant number, since it is smaller than the sum of its proper divisors (4652646925824).

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

1866981505536 is an equidigital number, since it uses as much as digits as its factorization.

1866981505536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622432 (or 622410 counting only the distinct ones).

The product of its (nonzero) digits is 46656000, while the sum is 63.

The spelling of 1866981505536 in words is "one trillion, eight hundred sixty-six billion, nine hundred eighty-one million, five hundred five thousand, five hundred thirty-six".