1378785408 has 512 divisors, whose sum is σ = 5231278080. Its totient is φ = 309657600.

The previous prime is 1378785389. The next prime is 1378785409. The reversal of 1378785408 is 8045878731.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (1378785409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6534423 + ... + 6534633.

It is an arithmetic number, because the mean of its divisors is an integer number (10217340).

Almost surely, 2^1378785408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1378785408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2615639040).

1378785408 is an abundant number, since it is smaller than the sum of its proper divisors (3852492672).

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

1378785408 is a wasteful number, since it uses less digits than its factorization.

1378785408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 51.

The square root of 1378785408 is about 37131.9997845524. Note that the first 3 decimals coincide. The cubic root of 1378785408 is about 1113.0095553718.

The spelling of 1378785408 in words is "one billion, three hundred seventy-eight million, seven hundred eighty-five thousand, four hundred eight".