1921818 has 8 divisors (see below), whose sum is σ = 3843648. Its totient is φ = 640604.

The previous prime is 1921813. The next prime is 1921819. The reversal of 1921818 is 8181291.

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

1921818 is an admirable number.

1921818 is a modest number, since divided by 1818 gives 192 as remainder.

It is not an unprimeable number, because it can be changed into a prime (1921813) 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, 160146 + ... + 160157.

It is an arithmetic number, because the mean of its divisors is an integer number (480456).

2^1921818 is an apocalyptic number.

1921818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1921818 is a wasteful number, since it uses less digits than its factorization.

1921818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320308.

The product of its digits is 1152, while the sum is 30.

The square root of 1921818 is about 1386.2965050811. The cubic root of 1921818 is about 124.3285166735.

The spelling of 1921818 in words is "one million, nine hundred twenty-one thousand, eight hundred eighteen".