1388989999 has 12 divisors (see below), whose sum is σ = 1468662888. Its totient is φ = 1312884720.

The previous prime is 1388989997. The next prime is 1388990063. The reversal of 1388989999 is 9999898831.

It is not a de Polignac number, because 1388989999 - 2¹ = 1388989997 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 (1388989997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24517 + ... + 58129.

It is an arithmetic number, because the mean of its divisors is an integer number (122388574).

Almost surely, 2^1388989999 is an apocalyptic number.

1388989999 is a deficient number, since it is larger than the sum of its proper divisors (79672889).

1388989999 is an equidigital number, since it uses as much as digits as its factorization.

1388989999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33718 (or 33687 counting only the distinct ones).

The product of its digits is 90699264, while the sum is 73.

The square root of 1388989999 is about 37269.1561347987. The cubic root of 1388989999 is about 1115.7486573893.

The spelling of 1388989999 in words is "one billion, three hundred eighty-eight million, nine hundred eighty-nine thousand, nine hundred ninety-nine".