1981511736 has 32 divisors (see below), whose sum is σ = 5023555200. Its totient is φ = 651200480.

The previous prime is 1981511713. The next prime is 1981511743. The reversal of 1981511736 is 6371151891.

1981511736 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579726 + ... + 583133.

It is an arithmetic number, because the mean of its divisors is an integer number (156986100).

Almost surely, 2^1981511736 is an apocalyptic number.

It is an amenable number.

1981511736 is an abundant number, since it is smaller than the sum of its proper divisors (3042043464).

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

1981511736 is a wasteful number, since it uses less digits than its factorization.

1981511736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162939 (or 1162935 counting only the distinct ones).

The product of its digits is 45360, while the sum is 42.

The square root of 1981511736 is about 44514.1745514842. The cubic root of 1981511736 is about 1256.0267331051.

The spelling of 1981511736 in words is "one billion, nine hundred eighty-one million, five hundred eleven thousand, seven hundred thirty-six".