1388439900 has 144 divisors (see below), whose sum is σ = 4567763200. Its totient is φ = 361609920.

The previous prime is 1388439869. The next prime is 1388439917. The reversal of 1388439900 is 99348831.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 110121 + ... + 122079.

Almost surely, 2^1388439900 is an apocalyptic number.

1388439900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1388439900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2283881600).

1388439900 is an abundant number, since it is smaller than the sum of its proper divisors (3179323300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1388439900 is a wasteful number, since it uses less digits than its factorization.

1388439900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12025 (or 12012 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 1388439900 is about 37261.7753200247. The cubic root of 1388439900 is about 1115.6013433300.

The spelling of 1388439900 in words is "one billion, three hundred eighty-eight million, four hundred thirty-nine thousand, nine hundred".