20105000 has 40 divisors (see below), whose sum is σ = 47117730. Its totient is φ = 8040000.

The previous prime is 20104993. The next prime is 20105009. The reversal of 20105000 is 50102.

It can be written as a sum of positive squares in 5 ways, for example, as 515524 + 19589476 = 718^2 + 4426^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×20105000² = 808422050000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is not an unprimeable number, because it can be changed into a prime (20105009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2990 + ... + 7010.

Almost surely, 2^20105000 is an apocalyptic number.

20105000 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 20105000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23558865).

20105000 is an abundant number, since it is smaller than the sum of its proper divisors (27012730).

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

20105000 is an equidigital number, since it uses as much as digits as its factorization.

20105000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4047 (or 4028 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 20105000 is about 4483.8599442891. The cubic root of 20105000 is about 271.9159558681.

Adding to 20105000 its reverse (50102), we get a palindrome (20155102).

The spelling of 20105000 in words is "twenty million, one hundred five thousand".