1978285 has 4 divisors (see below), whose sum is σ = 2373948. Its totient is φ = 1582624.

The previous prime is 1978267. The next prime is 1978289. The reversal of 1978285 is 5828791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1572516 + 405769 = 1254^2 + 637^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978285 - 2⁷ = 1978157 is a prime.

It is a super-2 number, since 2×1978285² = 7827223082450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1978285 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197824 + ... + 197833.

It is an arithmetic number, because the mean of its divisors is an integer number (593487).

2^1978285 is an apocalyptic number.

It is an amenable number.

1978285 is a deficient number, since it is larger than the sum of its proper divisors (395663).

1978285 is an equidigital number, since it uses as much as digits as its factorization.

1978285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395662.

The product of its digits is 40320, while the sum is 40.

The square root of 1978285 is about 1406.5151972162. The cubic root of 1978285 is about 125.5344582449.

The spelling of 1978285 in words is "one million, nine hundred seventy-eight thousand, two hundred eighty-five".