1989393664 has 36 divisors (see below), whose sum is σ = 4025451556. Its totient is φ = 981061632.

The previous prime is 1989393643. The next prime is 1989393709. The reversal of 1989393664 is 4663939891.

It can be written as a sum of positive squares in 2 ways, for example, as 1383840000 + 605553664 = 37200^2 + 24608^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1989393599 and 1989393608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34539 + ... + 71914.

Almost surely, 2^1989393664 is an apocalyptic number.

It is an amenable number.

1989393664 is an abundant number, since it is smaller than the sum of its proper divisors (2036057892).

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

1989393664 is an equidigital number, since it uses as much as digits as its factorization.

1989393664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106542 (or 106528 counting only the distinct ones).

The product of its digits is 7558272, while the sum is 58.

The square root of 1989393664 is about 44602.6194746452. The cubic root of 1989393664 is about 1257.6899102002.

The spelling of 1989393664 in words is "one billion, nine hundred eighty-nine million, three hundred ninety-three thousand, six hundred sixty-four".