1329788639 has 4 divisors (see below), whose sum is σ = 1333261056. Its totient is φ = 1326316224.

The previous prime is 1329788561. The next prime is 1329788651. The reversal of 1329788639 is 9368879231.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1329788639 - 2²⁴ = 1313011423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1329788699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1735634 + ... + 1736399.

It is an arithmetic number, because the mean of its divisors is an integer number (333315264).

Almost surely, 2^1329788639 is an apocalyptic number.

1329788639 is a deficient number, since it is larger than the sum of its proper divisors (3472417).

1329788639 is an equidigital number, since it uses as much as digits as its factorization.

1329788639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3472416.

The product of its digits is 3919104, while the sum is 56.

The square root of 1329788639 is about 36466.2671382745. The cubic root of 1329788639 is about 1099.6661904469. Note that the first 3 decimals are identical.

The spelling of 1329788639 in words is "one billion, three hundred twenty-nine million, seven hundred eighty-eight thousand, six hundred thirty-nine".