1981851392 has 72 divisors (see below), whose sum is σ = 4178222160. Its totient is φ = 935608320.

The previous prime is 1981851379. The next prime is 1981851437. The reversal of 1981851392 is 2931581891.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2105642 + ... + 2106582.

Almost surely, 2^1981851392 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981851392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2089111080).

1981851392 is an abundant number, since it is smaller than the sum of its proper divisors (2196370768).

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

1981851392 is an equidigital number, since it uses as much as digits as its factorization.

1981851392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409 (or 1395 counting only the distinct ones).

The product of its digits is 155520, while the sum is 47.

The square root of 1981851392 is about 44517.9895323228. The cubic root of 1981851392 is about 1256.0984952577.

The spelling of 1981851392 in words is "one billion, nine hundred eighty-one million, eight hundred fifty-one thousand, three hundred ninety-two".