1388820 has 48 divisors (see below), whose sum is σ = 3951360. Its totient is φ = 364416.

The previous prime is 1388819. The next prime is 1388837. The reversal of 1388820 is 288831.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4594 + ... + 4886.

It is an arithmetic number, because the mean of its divisors is an integer number (82320).

2^1388820 is an apocalyptic number.

1388820 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 1388820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1975680).

1388820 is an abundant number, since it is smaller than the sum of its proper divisors (2562540).

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

1388820 is a wasteful number, since it uses less digits than its factorization.

1388820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 1388820 is about 1178.4820745349. The cubic root of 1388820 is about 111.5703136568.

The spelling of 1388820 in words is "one million, three hundred eighty-eight thousand, eight hundred twenty".