1978668 has 60 divisors (see below), whose sum is σ = 5366592. Its totient is φ = 635040.

The previous prime is 1978663. The next prime is 1978673. The reversal of 1978668 is 8668791.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1978663) and next prime (1978673).

It is not an unprimeable number, because it can be changed into a prime (1978661) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9946 + ... + 10142.

2^1978668 is an apocalyptic number.

1978668 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2683296).

1978668 is an abundant number, since it is smaller than the sum of its proper divisors (3387924).

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

1978668 is a wasteful number, since it uses less digits than its factorization.

1978668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 233 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 1978668 is about 1406.6513427285. The cubic root of 1978668 is about 125.5425589643.

It can be divided in two parts, 19 and 78668, that added together give a palindrome (78687).

The spelling of 1978668 in words is "one million, nine hundred seventy-eight thousand, six hundred sixty-eight".