1981719168 has 256 divisors, whose sum is σ = 6251212800. Its totient is φ = 548352000.

The previous prime is 1981719161. The next prime is 1981719191. The reversal of 1981719168 is 8619171891.

It is a happy number.

It is a super-2 number, since 2×1981719168² = 7854421721637224448, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1981719168.

It is not an unprimeable number, because it can be changed into a prime (1981719161) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 8291593 + ... + 8291831.

It is an arithmetic number, because the mean of its divisors is an integer number (24418800).

Almost surely, 2^1981719168 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 1981719168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3125606400).

1981719168 is an abundant number, since it is smaller than the sum of its proper divisors (4269493632).

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

1981719168 is a wasteful number, since it uses less digits than its factorization.

1981719168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431 (or 419 counting only the distinct ones).

The product of its digits is 217728, while the sum is 51.

The square root of 1981719168 is about 44516.5044449809. The cubic root of 1981719168 is about 1256.0705600886.

The spelling of 1981719168 in words is "one billion, nine hundred eighty-one million, seven hundred nineteen thousand, one hundred sixty-eight".