1981843580 has 24 divisors (see below), whose sum is σ = 4274356128. Its totient is φ = 771311808.

The previous prime is 1981843537. The next prime is 1981843597. The reversal of 1981843580 is 853481891.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1338344 + ... + 1339823.

It is an arithmetic number, because the mean of its divisors is an integer number (178098172).

Almost surely, 2^1981843580 is an apocalyptic number.

1981843580 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981843580 is an abundant number, since it is smaller than the sum of its proper divisors (2292512548).

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

1981843580 is a wasteful number, since it uses less digits than its factorization.

1981843580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2678213 (or 2678211 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 47.

The square root of 1981843580 is about 44517.9017924250. The cubic root of 1981843580 is about 1256.0968448389.

The spelling of 1981843580 in words is "one billion, nine hundred eighty-one million, eight hundred forty-three thousand, five hundred eighty".