20831100 has 72 divisors (see below), whose sum is σ = 62912640. Its totient is φ = 5311680.

The previous prime is 20831093. The next prime is 20831119. The reversal of 20831100 is 113802.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20831100.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 5391 + ... + 8409.

Almost surely, 2^20831100 is an apocalyptic number.

20831100 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 20831100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31456320).

20831100 is an abundant number, since it is smaller than the sum of its proper divisors (42081540).

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

20831100 is a wasteful number, since it uses less digits than its factorization.

20831100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3059 (or 3052 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 20831100 is about 4564.1099899104. The cubic root of 20831100 is about 275.1507713176.

Adding to 20831100 its reverse (113802), we get a palindrome (20944902).

The spelling of 20831100 in words is "twenty million, eight hundred thirty-one thousand, one hundred".