1391818 has 8 divisors (see below), whose sum is σ = 2116548. Its totient is φ = 686304.

The previous prime is 1391779. The next prime is 1391849. The reversal of 1391818 is 8181931.

It can be written as a sum of positive squares in 2 ways, for example, as 1361889 + 29929 = 1167^2 + 173^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1391818.

It is an unprimeable number.

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, 4621 + ... + 4912.

2^1391818 is an apocalyptic number.

1391818 is a deficient number, since it is larger than the sum of its proper divisors (724730).

1391818 is an equidigital number, since it uses as much as digits as its factorization.

1391818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9608.

The product of its digits is 1728, while the sum is 31.

The square root of 1391818 is about 1179.7533640554. The cubic root of 1391818 is about 111.6505370134.

It can be divided in two parts, 1391 and 818, that added together give a square (2209 = 47²).

The spelling of 1391818 in words is "one million, three hundred ninety-one thousand, eight hundred eighteen".