20684500 has 48 divisors (see below), whose sum is σ = 46322640. Its totient is φ = 8064000.

The previous prime is 20684479. The next prime is 20684509. The reversal of 20684500 is 548602.

It can be written as a sum of positive squares in 8 ways, for example, as 14394436 + 6290064 = 3794^2 + 2508^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20684509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19996 + ... + 21004.

It is an arithmetic number, because the mean of its divisors is an integer number (965055).

Almost surely, 2^20684500 is an apocalyptic number.

20684500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20684500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23161320).

20684500 is an abundant number, since it is smaller than the sum of its proper divisors (25638140).

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

20684500 is a wasteful number, since it uses less digits than its factorization.

20684500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069 (or 1057 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20684500 is about 4548.0215478821. The cubic root of 20684500 is about 274.5037883669.

It can be divided in two parts, 20 and 684500, that multiplied together give a square (13690000 = 3700²).

The spelling of 20684500 in words is "twenty million, six hundred eighty-four thousand, five hundred".