1918885 has 4 divisors (see below), whose sum is σ = 2302668. Its totient is φ = 1535104.

The previous prime is 1918879. The next prime is 1918897. The reversal of 1918885 is 5888191.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5888191 = 97 ⋅60703.

It can be written as a sum of positive squares in 2 ways, for example, as 1046529 + 872356 = 1023^2 + 934^2 .

It is a cyclic number.

It is not a de Polignac number, because 1918885 - 2¹³ = 1910693 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191884 + ... + 191893.

It is an arithmetic number, because the mean of its divisors is an integer number (575667).

2^1918885 is an apocalyptic number.

It is an amenable number.

1918885 is a deficient number, since it is larger than the sum of its proper divisors (383783).

1918885 is an equidigital number, since it uses as much as digits as its factorization.

1918885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383782.

The product of its digits is 23040, while the sum is 40.

The square root of 1918885 is about 1385.2382466565. The cubic root of 1918885 is about 124.2652361054.

The spelling of 1918885 in words is "one million, nine hundred eighteen thousand, eight hundred eighty-five".