1388443680 has 576 divisors, whose sum is σ = 5501478528. Its totient is φ = 328458240.

The previous prime is 1388443633. The next prime is 1388443681. The reversal of 1388443680 is 863448831.

1388443680 is a `hidden beast` number, since 138 + 8 + 4 + 436 + 80 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388443681) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20723007 + ... + 20723073.

It is an arithmetic number, because the mean of its divisors is an integer number (9551178).

Almost surely, 2^1388443680 is an apocalyptic number.

1388443680 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 1388443680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2750739264).

1388443680 is an abundant number, since it is smaller than the sum of its proper divisors (4113034848).

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

1388443680 is a wasteful number, since it uses less digits than its factorization.

1388443680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 1388443680 is about 37261.8260422111. The cubic root of 1388443680 is about 1115.6023557299.

The spelling of 1388443680 in words is "one billion, three hundred eighty-eight million, four hundred forty-three thousand, six hundred eighty".