221331072 has 64 divisors (see below), whose sum is σ = 606908160. Its totient is φ = 71393280.

The previous prime is 221331053. The next prime is 221331091. The reversal of 221331072 is 270133122.

It is an interprime number because it is at equal distance from previous prime (221331053) and next prime (221331091).

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2608 + ... + 21200.

It is an arithmetic number, because the mean of its divisors is an integer number (9482940).

Almost surely, 2^221331072 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 221331072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303454080).

221331072 is an abundant number, since it is smaller than the sum of its proper divisors (385577088).

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

221331072 is a wasteful number, since it uses less digits than its factorization.

221331072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18641 (or 18629 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 221331072 is about 14877.1997365096. The cubic root of 221331072 is about 604.8961158516.

Adding to 221331072 its reverse (270133122), we get a palindrome (491464194).

The spelling of 221331072 in words is "two hundred twenty-one million, three hundred thirty-one thousand, seventy-two".