1388211756 has 12 divisors (see below), whose sum is σ = 3239160792. Its totient is φ = 462737248.

The previous prime is 1388211749. The next prime is 1388211829. The reversal of 1388211756 is 6571128831.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

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, 57842145 + ... + 57842168.

It is an arithmetic number, because the mean of its divisors is an integer number (269930066).

Almost surely, 2^1388211756 is an apocalyptic number.

It is an amenable number.

1388211756 is an abundant number, since it is smaller than the sum of its proper divisors (1850949036).

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

1388211756 is a wasteful number, since it uses less digits than its factorization.

1388211756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115684320 (or 115684318 counting only the distinct ones).

The product of its digits is 80640, while the sum is 42.

The square root of 1388211756 is about 37258.7138264326. The cubic root of 1388211756 is about 1115.5402359690.

The spelling of 1388211756 in words is "one billion, three hundred eighty-eight million, two hundred eleven thousand, seven hundred fifty-six".