1978218 has 48 divisors (see below), whose sum is σ = 4769856. Its totient is φ = 587520.

The previous prime is 1978201. The next prime is 1978219. The reversal of 1978218 is 8128791.

It is not an unprimeable number, because it can be changed into a prime (1978219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19155 + ... + 19257.

It is an arithmetic number, because the mean of its divisors is an integer number (99372).

2^1978218 is an apocalyptic number.

1978218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2384928).

1978218 is an abundant number, since it is smaller than the sum of its proper divisors (2791638).

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

1978218 is a wasteful number, since it uses less digits than its factorization.

1978218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219 (or 216 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1978218 is about 1406.4913792839. The cubic root of 1978218 is about 125.5330410403.

The spelling of 1978218 in words is "one million, nine hundred seventy-eight thousand, two hundred eighteen".