1438640784 has 400 divisors, whose sum is σ = 5140395200. Its totient is φ = 384072192.

The previous prime is 1438640747. The next prime is 1438640789. The reversal of 1438640784 is 4870468341.

It is not an unprimeable number, because it can be changed into a prime (1438640789) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 19707372 + ... + 19707444.

It is an arithmetic number, because the mean of its divisors is an integer number (12850988).

Almost surely, 2^1438640784 is an apocalyptic number.

1438640784 is a gapful number since it is divisible by the number (14) 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 1438640784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2570197600).

1438640784 is an abundant number, since it is smaller than the sum of its proper divisors (3701754416).

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

1438640784 is an equidigital number, since it uses as much as digits as its factorization.

1438640784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The square root of 1438640784 is about 37929.4184505906. The cubic root of 1438640784 is about 1128.8878252471.

The spelling of 1438640784 in words is "one billion, four hundred thirty-eight million, six hundred forty thousand, seven hundred eighty-four".