20860020 has 108 divisors (see below), whose sum is σ = 67384044. Its totient is φ = 5222400.

The previous prime is 20860001. The next prime is 20860027. The reversal of 20860020 is 2006802.

It can be written as a sum of positive squares in 6 ways, for example, as 6022116 + 14837904 = 2454^2 + 3852^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20859975 and 20860002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20860027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 51820 + ... + 52220.

Almost surely, 2^20860020 is an apocalyptic number.

20860020 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 20860020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33692022).

20860020 is an abundant number, since it is smaller than the sum of its proper divisors (46524024).

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

20860020 is a wasteful number, since it uses less digits than its factorization.

20860020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20860020 is about 4567.2770881566. The cubic root of 20860020 is about 275.2780438527.

Adding to 20860020 its reverse (2006802), we get a palindrome (22866822).

The spelling of 20860020 in words is "twenty million, eight hundred sixty thousand, twenty".