211221010000 has 400 divisors, whose sum is σ = 686650301568. Its totient is φ = 60768000000.

The previous prime is 211221009953. The next prime is 211221010003. The reversal of 211221010000 is 10122112.

It is a tau number, because it is divible by the number of its divisors (400).

It is a super-2 number, since 2×211221010000² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221010003) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 9999450 + ... + 10020550.

Almost surely, 2^211221010000 is an apocalyptic number.

211221010000 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 211221010000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343325150784).

211221010000 is an abundant number, since it is smaller than the sum of its proper divisors (475429291568).

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

211221010000 is a wasteful number, since it uses less digits than its factorization.

211221010000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21160 (or 21139 counting only the distinct ones).

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

Adding to 211221010000 its reverse (10122112), we get a palindrome (211231132112).

The spelling of 211221010000 in words is "two hundred eleven billion, two hundred twenty-one million, ten thousand".