1378738656 has 72 divisors (see below), whose sum is σ = 3957519384. Its totient is φ = 455274240.

The previous prime is 1378738649. The next prime is 1378738687. The reversal of 1378738656 is 6568378731.

1378738656 is a `hidden beast` number, since 137 + 87 + 386 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8446 + ... + 53186.

It is an arithmetic number, because the mean of its divisors is an integer number (54965547).

Almost surely, 2^1378738656 is an apocalyptic number.

1378738656 is a gapful number since it is divisible by the number (16) 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 1378738656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1978759692).

1378738656 is an abundant number, since it is smaller than the sum of its proper divisors (2578780728).

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

1378738656 is a wasteful number, since it uses less digits than its factorization.

1378738656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44864 (or 44853 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The square root of 1378738656 is about 37131.3702413471. The cubic root of 1378738656 is about 1112.9969752148.

The spelling of 1378738656 in words is "one billion, three hundred seventy-eight million, seven hundred thirty-eight thousand, six hundred fifty-six".