1388533385 has 4 divisors (see below), whose sum is σ = 1666240068. Its totient is φ = 1110826704.

The previous prime is 1388533381. The next prime is 1388533387. The reversal of 1388533385 is 5833358831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5833358831 = 23 ⋅253624297.

It can be written as a sum of positive squares in 2 ways, for example, as 480354889 + 908178496 = 21917^2 + 30136^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388533385 - 2² = 1388533381 is a prime.

It is a super-2 number, since 2×1388533385² = 3856049922519116450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388533381) 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, 138853334 + ... + 138853343.

It is an arithmetic number, because the mean of its divisors is an integer number (416560017).

Almost surely, 2^1388533385 is an apocalyptic number.

It is an amenable number.

1388533385 is a deficient number, since it is larger than the sum of its proper divisors (277706683).

1388533385 is an equidigital number, since it uses as much as digits as its factorization.

1388533385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277706682.

The product of its digits is 1036800, while the sum is 47.

The square root of 1388533385 is about 37263.0297345774. The cubic root of 1388533385 is about 1115.6263809402.

The spelling of 1388533385 in words is "one billion, three hundred eighty-eight million, five hundred thirty-three thousand, three hundred eighty-five".