1289693664 has 120 divisors (see below), whose sum is σ = 4334864688. Its totient is φ = 368478720.

The previous prime is 1289693641. The next prime is 1289693689. The reversal of 1289693664 is 4663969821.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1289693664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17397 + ... + 53684.

Almost surely, 2^1289693664 is an apocalyptic number.

1289693664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1289693664 is an abundant number, since it is smaller than the sum of its proper divisors (3045171024).

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

1289693664 is an equidigital number, since it uses as much as digits as its factorization.

1289693664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71110 (or 71093 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 1289693664 is about 35912.3051891688. The cubic root of 1289693664 is about 1088.5010577788.

The spelling of 1289693664 in words is "one billion, two hundred eighty-nine million, six hundred ninety-three thousand, six hundred sixty-four".