1881979809840 has 800 divisors, whose sum is σ = 7154498957760. Its totient is φ = 457608019968.

The previous prime is 1881979809823. The next prime is 1881979809847. The reversal of 1881979809840 is 489089791881.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (1881979809847) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1821857964 + ... + 1821858996.

Almost surely, 2^{1881979809840} is an apocalyptic number.

1881979809840 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 1881979809840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3577249478880).

1881979809840 is an abundant number, since it is smaller than the sum of its proper divisors (5272519147920).

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

1881979809840 is an equidigital number, since it uses as much as digits as its factorization.

1881979809840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1175 (or 1145 counting only the distinct ones).

The product of its (nonzero) digits is 83607552, while the sum is 72.

The spelling of 1881979809840 in words is "one trillion, eight hundred eighty-one billion, nine hundred seventy-nine million, eight hundred nine thousand, eight hundred forty".