20111021200 has 90 divisors (see below), whose sum is σ = 50993921634. Its totient is φ = 7620963840.

The previous prime is 20111021197. The next prime is 20111021237. The reversal of 20111021200 is 212011102.

It can be written as a sum of positive squares in 3 ways, for example, as 6625308816 + 13485712384 = 81396^2 + 116128^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

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 17 ways as a sum of consecutive naturals, for example, 74764 + ... + 214036.

Almost surely, 2^20111021200 is an apocalyptic number.

20111021200 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 20111021200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25496960817).

20111021200 is an abundant number, since it is smaller than the sum of its proper divisors (30882900434).

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

20111021200 is a wasteful number, since it uses less digits than its factorization.

20111021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139329 (or 139299 counting only the distinct ones).

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

Adding to 20111021200 its reverse (212011102), we get a palindrome (20323032302).

The spelling of 20111021200 in words is "twenty billion, one hundred eleven million, twenty-one thousand, two hundred".