1388077440 has 128 divisors (see below), whose sum is σ = 4468089600. Its totient is φ = 366508032.

The previous prime is 1388077429. The next prime is 1388077463. The reversal of 1388077440 is 447708831.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 1388077392 and 1388077401.

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, 194251 + ... + 201269.

It is an arithmetic number, because the mean of its divisors is an integer number (34906950).

Almost surely, 2^1388077440 is an apocalyptic number.

1388077440 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 1388077440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2234044800).

1388077440 is an abundant number, since it is smaller than the sum of its proper divisors (3080012160).

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

1388077440 is a wasteful number, since it uses less digits than its factorization.

1388077440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7144 (or 7132 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 42.

The square root of 1388077440 is about 37256.9113051525. The cubic root of 1388077440 is about 1115.5042568915.

The spelling of 1388077440 in words is "one billion, three hundred eighty-eight million, seventy-seven thousand, four hundred forty".