1388815538 has 32 divisors (see below), whose sum is σ = 2300538240. Its totient is φ = 623554560.

The previous prime is 1388815537. The next prime is 1388815567. The reversal of 1388815538 is 8355188831.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1388815537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1742156 + ... + 1742952.

It is an arithmetic number, because the mean of its divisors is an integer number (71891820).

Almost surely, 2^1388815538 is an apocalyptic number.

1388815538 is a deficient number, since it is larger than the sum of its proper divisors (911722702).

1388815538 is a wasteful number, since it uses less digits than its factorization.

1388815538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1682.

The product of its digits is 921600, while the sum is 50.

The square root of 1388815538 is about 37266.8155065603. The cubic root of 1388815538 is about 1115.7019417237.

The spelling of 1388815538 in words is "one billion, three hundred eighty-eight million, eight hundred fifteen thousand, five hundred thirty-eight".