1388791 has 2 divisors, whose sum is σ = 1388792. Its totient is φ = 1388790.

The previous prime is 1388789. The next prime is 1388797. The reversal of 1388791 is 1978831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1388791 - 2¹ = 1388789 is a prime.

Together with 1388789, it forms a pair of twin primes.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1388791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1388797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694395 + 694396.

It is an arithmetic number, because the mean of its divisors is an integer number (694396).

2^1388791 is an apocalyptic number.

1388791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1388791 is an equidigital number, since it uses as much as digits as its factorization.

1388791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 37.

The square root of 1388791 is about 1178.4697705075. The cubic root of 1388791 is about 111.5695370835.

It can be divided in two parts, 13 and 88791, that added together give a square (88804 = 298²).

The spelling of 1388791 in words is "one million, three hundred eighty-eight thousand, seven hundred ninety-one".