1989397836 has 36 divisors (see below), whose sum is σ = 5031287352. Its totient is φ = 662798784.

The previous prime is 1989397801. The next prime is 1989397841. The reversal of 1989397836 is 6387939891.

It is a tau number, because it is divible by the number of its divisors (36).

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 11 ways as a sum of consecutive naturals, for example, 64675 + ... + 90341.

It is an arithmetic number, because the mean of its divisors is an integer number (139757982).

Almost surely, 2^1989397836 is an apocalyptic number.

It is an amenable number.

1989397836 is an abundant number, since it is smaller than the sum of its proper divisors (3041889516).

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

1989397836 is a wasteful number, since it uses less digits than its factorization.

1989397836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27830 (or 27825 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The square root of 1989397836 is about 44602.6662431743. Note that the first 3 decimals coincide. The cubic root of 1989397836 is about 1257.6907893757.

The spelling of 1989397836 in words is "one billion, nine hundred eighty-nine million, three hundred ninety-seven thousand, eight hundred thirty-six".