1388891 has 4 divisors (see below), whose sum is σ = 1587312. Its totient is φ = 1190472.

The previous prime is 1388887. The next prime is 1388927. The reversal of 1388891 is 1988831.

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

It is a cyclic number.

It is not a de Polignac number, because 1388891 - 2² = 1388887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99200 + ... + 99213.

It is an arithmetic number, because the mean of its divisors is an integer number (396828).

2^1388891 is an apocalyptic number.

1388891 is a deficient number, since it is larger than the sum of its proper divisors (198421).

1388891 is an equidigital number, since it uses as much as digits as its factorization.

1388891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198420.

The product of its digits is 13824, while the sum is 38.

The square root of 1388891 is about 1178.5121976458. The cubic root of 1388891 is about 111.5722148769.

The spelling of 1388891 in words is "one million, three hundred eighty-eight thousand, eight hundred ninety-one".