21201111000 has 192 divisors, whose sum is σ = 73597661280. Its totient is φ = 5500742400.

The previous prime is 21201110969. The next prime is 21201111007. The reversal of 21201111000 is 11110212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201111007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 301167 + ... + 364833.

Almost surely, 2^21201111000 is an apocalyptic number.

21201111000 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 21201111000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36798830640).

21201111000 is an abundant number, since it is smaller than the sum of its proper divisors (52396550280).

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

21201111000 is a wasteful number, since it uses less digits than its factorization.

21201111000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63731 (or 63714 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21201111000 its reverse (11110212), we get a palindrome (21212221212).

The spelling of 21201111000 in words is "twenty-one billion, two hundred one million, one hundred eleven thousand".