1981020064 has 48 divisors (see below), whose sum is σ = 4167563400. Its totient is φ = 923664384.

The previous prime is 1981020031. The next prime is 1981020109. The reversal of 1981020064 is 4600201891.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1773083664 + 207936400 = 42108^2 + 14420^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42592 + ... + 76000.

Almost surely, 2^1981020064 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 1981020064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2083781700).

1981020064 is an abundant number, since it is smaller than the sum of its proper divisors (2186543336).

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

1981020064 is a wasteful number, since it uses less digits than its factorization.

1981020064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33545 (or 33537 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1981020064 is about 44508.6515634882. The cubic root of 1981020064 is about 1255.9228386476.

The spelling of 1981020064 in words is "one billion, nine hundred eighty-one million, twenty thousand, sixty-four".