1388605806 has 72 divisors (see below), whose sum is σ = 3506666904. Its totient is φ = 395972640.

The previous prime is 1388605793. The next prime is 1388605807. The reversal of 1388605806 is 6085068831.

1388605806 is a `hidden beast` number, since 1 + 3 + 8 + 8 + 60 + 580 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388605807) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 574741 + ... + 577151.

It is an arithmetic number, because the mean of its divisors is an integer number (48703707).

Almost surely, 2^1388605806 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1388605806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1753333452).

1388605806 is an abundant number, since it is smaller than the sum of its proper divisors (2118061098).

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

1388605806 is a wasteful number, since it uses less digits than its factorization.

1388605806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3086 (or 3076 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 1388605806 is about 37264.0014759553. The cubic root of 1388605806 is about 1115.6457763143.

The spelling of 1388605806 in words is "one billion, three hundred eighty-eight million, six hundred five thousand, eight hundred six".