1388440811 has 4 divisors (see below), whose sum is σ = 1390450824. Its totient is φ = 1386430800.

The previous prime is 1388440787. The next prime is 1388440819. The reversal of 1388440811 is 1180448831.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1388440811 is a prime.

It is a Duffinian number.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1003970 + ... + 1005351.

It is an arithmetic number, because the mean of its divisors is an integer number (347612706).

Almost surely, 2^1388440811 is an apocalyptic number.

1388440811 is a deficient number, since it is larger than the sum of its proper divisors (2010013).

1388440811 is an equidigital number, since it uses as much as digits as its factorization.

1388440811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2010012.

The product of its (nonzero) digits is 24576, while the sum is 38.

The square root of 1388440811 is about 37261.7875443463. The cubic root of 1388440811 is about 1115.6015873239.

The spelling of 1388440811 in words is "one billion, three hundred eighty-eight million, four hundred forty thousand, eight hundred eleven".