1388127789 has 6 divisors (see below), whose sum is σ = 2005073486. Its totient is φ = 925418520.

The previous prime is 1388127787. The next prime is 1388127803. The reversal of 1388127789 is 9877218831.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1272134889 + 115992900 = 35667^2 + 10770^2 .

It is not a de Polignac number, because 1388127789 - 2¹ = 1388127787 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 (1388127787) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77118202 + ... + 77118219.

Almost surely, 2^1388127789 is an apocalyptic number.

It is an amenable number.

1388127789 is a deficient number, since it is larger than the sum of its proper divisors (616945697).

1388127789 is a wasteful number, since it uses less digits than its factorization.

1388127789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154236427 (or 154236424 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The square root of 1388127789 is about 37257.5869991603. The cubic root of 1388127789 is about 1115.5177440941.

The spelling of 1388127789 in words is "one billion, three hundred eighty-eight million, one hundred twenty-seven thousand, seven hundred eighty-nine".