221211000 has 160 divisors (see below), whose sum is σ = 773538480. Its totient is φ = 58968000.

The previous prime is 221210993. The next prime is 221211017. The reversal of 221211000 is 112122.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 79635 + ... + 82365.

Almost surely, 2^221211000 is an apocalyptic number.

221211000 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 221211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386769240).

221211000 is an abundant number, since it is smaller than the sum of its proper divisors (552327480).

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

221211000 is a wasteful number, since it uses less digits than its factorization.

221211000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2764 (or 2741 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 221211000 is about 14873.1637522082. The cubic root of 221211000 is about 604.7867107813.

Adding to 221211000 its reverse (112122), we get a palindrome (221323122).

The spelling of 221211000 in words is "two hundred twenty-one million, two hundred eleven thousand".