1861486365440 has 144 divisors (see below), whose sum is σ = 4815447483168. Its totient is φ = 685368803328.

The previous prime is 1861486365397. The next prime is 1861486365451. The reversal of 1861486365440 is 445636841681.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5715467 + ... + 6032373.

It is an arithmetic number, because the mean of its divisors is an integer number (33440607522).

Almost surely, 2^{1861486365440} is an apocalyptic number.

1861486365440 is a gapful number since it is divisible by the number (10) 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 1861486365440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2407723741584).

1861486365440 is an abundant number, since it is smaller than the sum of its proper divisors (2953961117728).

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

1861486365440 is a wasteful number, since it uses less digits than its factorization.

1861486365440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317294 (or 317280 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 56.

The spelling of 1861486365440 in words is "one trillion, eight hundred sixty-one billion, four hundred eighty-six million, three hundred sixty-five thousand, four hundred forty".