981636 has 24 divisors (see below), whose sum is σ = 2308320. Its totient is φ = 324672.

The previous prime is 981623. The next prime is 981637. The reversal of 981636 is 636189.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 981597 and 981606.

It is not an unprimeable number, because it can be changed into a prime (981637) by changing a digit.

981636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 1920 + ... + 2376.

It is an arithmetic number, because the mean of its divisors is an integer number (96180).

2⁹⁸¹⁶³⁶ is an apocalyptic number.

It is an amenable number.

981636 is an abundant number, since it is smaller than the sum of its proper divisors (1326684).

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

981636 is a wasteful number, since it uses less digits than its factorization.

981636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 641 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 981636 is about 990.7754538744. The cubic root of 981636 is about 99.3840808916.

The spelling of 981636 in words is "nine hundred eighty-one thousand, six hundred thirty-six".