20685630 has 64 divisors (see below), whose sum is σ = 57231360. Its totient is φ = 4687104.

The previous prime is 20685629. The next prime is 20685631. The reversal of 20685630 is 3658602.

It is an interprime number because it is at equal distance from previous prime (20685629) and next prime (20685631).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20685631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28411 + ... + 29129.

It is an arithmetic number, because the mean of its divisors is an integer number (894240).

Almost surely, 2^20685630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20685630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28615680).

20685630 is an abundant number, since it is smaller than the sum of its proper divisors (36545730).

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

20685630 is a wasteful number, since it uses less digits than its factorization.

20685630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 20685630 is about 4548.1457760279. The cubic root of 20685630 is about 274.5087870154.

The spelling of 20685630 in words is "twenty million, six hundred eighty-five thousand, six hundred thirty".