1981841904 has 400 divisors, whose sum is σ = 7029073920. Its totient is φ = 529079040.

The previous prime is 1981841893. The next prime is 1981841941. The reversal of 1981841904 is 4091481891.

It is a self number, because there is not a number n which added to its sum of digits gives 1981841904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 63930369 + ... + 63930399.

Almost surely, 2^1981841904 is an apocalyptic number.

1981841904 is a gapful number since it is divisible by the number (14) 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 1981841904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3514536960).

1981841904 is an abundant number, since it is smaller than the sum of its proper divisors (5047232016).

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

1981841904 is an frugal number, since it uses more digits than its factorization.

1981841904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 1981841904 is about 44517.8829685330. The cubic root of 1981841904 is about 1256.0964907546.

The spelling of 1981841904 in words is "one billion, nine hundred eighty-one million, eight hundred forty-one thousand, nine hundred four".