20871100 has 36 divisors (see below), whose sum is σ = 45715824. Its totient is φ = 8270080.

The previous prime is 20871077. The next prime is 20871107. The reversal of 20871100 is 117802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10377 + ... + 12223.

It is an arithmetic number, because the mean of its divisors is an integer number (1269884).

Almost surely, 2^20871100 is an apocalyptic number.

20871100 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 20871100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22857912).

20871100 is an abundant number, since it is smaller than the sum of its proper divisors (24844724).

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

20871100 is a wasteful number, since it uses less digits than its factorization.

20871100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1974 (or 1967 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 20871100 is about 4568.4899036771. The cubic root of 20871100 is about 275.3267740850.

Adding to 20871100 its reverse (117802), we get a palindrome (20988902).

The spelling of 20871100 in words is "twenty million, eight hundred seventy-one thousand, one hundred".