1978636 has 24 divisors (see below), whose sum is σ = 3813264. Its totient is φ = 890880.

The previous prime is 1978631. The next prime is 1978661. The reversal of 1978636 is 6368791.

It is a d-powerful number, because it can be written as 1 + 9² + 7⁵ + 8 + 6⁷ + 3⁷ + 6⁸ .

It is not an unprimeable number, because it can be changed into a prime (1978631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8376 + ... + 8608.

It is an arithmetic number, because the mean of its divisors is an integer number (158886).

2^1978636 is an apocalyptic number.

It is an amenable number.

1978636 is a deficient number, since it is larger than the sum of its proper divisors (1834628).

1978636 is a wasteful number, since it uses less digits than its factorization.

1978636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 439 counting only the distinct ones).

The product of its digits is 54432, while the sum is 40.

The square root of 1978636 is about 1406.6399681511. The cubic root of 1978636 is about 125.5418821818.

The spelling of 1978636 in words is "one million, nine hundred seventy-eight thousand, six hundred thirty-six".