20985630 has 16 divisors (see below), whose sum is σ = 50365584. Its totient is φ = 5596160.

The previous prime is 20985617. The next prime is 20985649. The reversal of 20985630 is 3658902.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20985591 and 20985600.

It is a congruent number.

It is an unprimeable 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, 349731 + ... + 349790.

It is an arithmetic number, because the mean of its divisors is an integer number (3147849).

Almost surely, 2^20985630 is an apocalyptic number.

20985630 is an abundant number, since it is smaller than the sum of its proper divisors (29379954).

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

20985630 is a wasteful number, since it uses less digits than its factorization.

20985630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699531.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20985630 is about 4581.0075311006. The cubic root of 20985630 is about 275.8294735320.

The spelling of 20985630 in words is "twenty million, nine hundred eighty-five thousand, six hundred thirty".