1978290 has 64 divisors (see below), whose sum is σ = 5598720. Its totient is φ = 495360.

The previous prime is 1978289. The next prime is 1978297. The reversal of 1978290 is 928791.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1978297) 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 31 ways as a sum of consecutive naturals, for example, 4375 + ... + 4805.

It is an arithmetic number, because the mean of its divisors is an integer number (87480).

2^1978290 is an apocalyptic number.

1978290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2799360).

1978290 is an abundant number, since it is smaller than the sum of its proper divisors (3620430).

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

1978290 is a wasteful number, since it uses less digits than its factorization.

1978290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 458 counting only the distinct ones).

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

The square root of 1978290 is about 1406.5169746576. The cubic root of 1978290 is about 125.5345640051.

The spelling of 1978290 in words is "one million, nine hundred seventy-eight thousand, two hundred ninety".