20111000 has 192 divisors, whose sum is σ = 61663680. Its totient is φ = 5990400.

The previous prime is 20110997. The next prime is 20111011. The reversal of 20111000 is 11102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1182992 + ... + 1183008.

It is an arithmetic number, because the mean of its divisors is an integer number (321165).

Almost surely, 2^20111000 is an apocalyptic number.

20111000 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 20111000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30831840).

20111000 is an abundant number, since it is smaller than the sum of its proper divisors (41552680).

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

20111000 is a wasteful number, since it uses less digits than its factorization.

20111000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 20111000 is about 4484.5289607717. The cubic root of 20111000 is about 271.9430027630.

Adding to 20111000 its reverse (11102), we get a palindrome (20122102).

The spelling of 20111000 in words is "twenty million, one hundred eleven thousand".