2019978 has 40 divisors (see below), whose sum is σ = 4662372. Its totient is φ = 653184.

The previous prime is 2019977. The next prime is 2020001. The reversal of 2019978 is 8799102.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1996569 + 23409 = 1413^2 + 153^2 .

It is a super-2 number, since 2×2019978² = 8160622240968, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2019973) 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 19 ways as a sum of consecutive naturals, for example, 5826 + ... + 6162.

2^2019978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2019978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2331186).

2019978 is an abundant number, since it is smaller than the sum of its proper divisors (2642394).

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

2019978 is a wasteful number, since it uses less digits than its factorization.

2019978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 2019978 is about 1421.2593007611. The cubic root of 2019978 is about 126.4102275680.

The spelling of 2019978 in words is "two million, nineteen thousand, nine hundred seventy-eight".