1388916665 has 16 divisors (see below), whose sum is σ = 1682242560. Its totient is φ = 1100820480.

The previous prime is 1388916649. The next prime is 1388916667. The reversal of 1388916665 is 5666198831.

It is not a de Polignac number, because 1388916665 - 2⁴ = 1388916649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1388916667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 242606 + ... + 248264.

It is an arithmetic number, because the mean of its divisors is an integer number (105140160).

Almost surely, 2^1388916665 is an apocalyptic number.

It is an amenable number.

1388916665 is a deficient number, since it is larger than the sum of its proper divisors (293325895).

1388916665 is a wasteful number, since it uses less digits than its factorization.

1388916665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6112.

The product of its digits is 1866240, while the sum is 53.

The square root of 1388916665 is about 37268.1722787689. The cubic root of 1388916665 is about 1115.7290211183.

The spelling of 1388916665 in words is "one billion, three hundred eighty-eight million, nine hundred sixteen thousand, six hundred sixty-five".