221211648 has 264 divisors, whose sum is σ = 762990592. Its totient is φ = 62705664.

The previous prime is 221211643. The next prime is 221211673. The reversal of 221211648 is 846112122.

221211648 is a `hidden beast` number, since 2 + 2 + 1 + 2 + 11 + 648 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (221211643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1741761 + ... + 1741887.

Almost surely, 2^221211648 is an apocalyptic number.

221211648 is a gapful number since it is divisible by the number (28) 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 221211648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (381495296).

221211648 is an abundant number, since it is smaller than the sum of its proper divisors (541778944).

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

221211648 is an equidigital number, since it uses as much as digits as its factorization.

221211648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 139 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 221211648 is about 14873.1855363940. The cubic root of 221211648 is about 604.7873013207.

The spelling of 221211648 in words is "two hundred twenty-one million, two hundred eleven thousand, six hundred forty-eight".