1388440812 has 24 divisors (see below), whose sum is σ = 3534213312. Its totient is φ = 420739600.

The previous prime is 1388440787. The next prime is 1388440819. The reversal of 1388440812 is 2180448831.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1388440819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5259114 + ... + 5259377.

It is an arithmetic number, because the mean of its divisors is an integer number (147258888).

Almost surely, 2^1388440812 is an apocalyptic number.

1388440812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1388440812 is an abundant number, since it is smaller than the sum of its proper divisors (2145772500).

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

1388440812 is a wasteful number, since it uses less digits than its factorization.

1388440812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10518509 (or 10518507 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 39.

The square root of 1388440812 is about 37261.7875577649. The cubic root of 1388440812 is about 1115.6015875917.

The spelling of 1388440812 in words is "one billion, three hundred eighty-eight million, four hundred forty thousand, eight hundred twelve".