1388820100 has 72 divisors (see below), whose sum is σ = 3203935560. Its totient is φ = 520734720.

The previous prime is 1388820053. The next prime is 1388820113. The reversal of 1388820100 is 10288831.

It can be written as a sum of positive squares in 12 ways, for example, as 271656324 + 1117163776 = 16482^2 + 33424^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 455782 + ... + 458818.

It is an arithmetic number, because the mean of its divisors is an integer number (44499105).

Almost surely, 2^1388820100 is an apocalyptic number.

1388820100 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 1388820100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1601967780).

1388820100 is an abundant number, since it is smaller than the sum of its proper divisors (1815115460).

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

1388820100 is a wasteful number, since it uses less digits than its factorization.

1388820100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3337 (or 3330 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 1388820100 is about 37266.8767137790. The cubic root of 1388820100 is about 1115.7031633466.

The spelling of 1388820100 in words is "one billion, three hundred eighty-eight million, eight hundred twenty thousand, one hundred".