221406648 has 64 divisors (see below), whose sum is σ = 597542400. Its totient is φ = 68154240.

The previous prime is 221406643. The next prime is 221406667. The reversal of 221406648 is 846604122.

221406648 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221406643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9093 + ... + 22923.

It is an arithmetic number, because the mean of its divisors is an integer number (9336600).

Almost surely, 2^221406648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221406648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298771200).

221406648 is an abundant number, since it is smaller than the sum of its proper divisors (376135752).

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

221406648 is a wasteful number, since it uses less digits than its factorization.

221406648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13892 (or 13888 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 221406648 is about 14879.7395138490. The cubic root of 221406648 is about 604.9649575587.

The spelling of 221406648 in words is "two hundred twenty-one million, four hundred six thousand, six hundred forty-eight".