221091072 has 72 divisors (see below), whose sum is σ = 590634240. Its totient is φ = 73420800.

The previous prime is 221091053. The next prime is 221091127. The reversal of 221091072 is 270190122.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 367572 + ... + 368172.

Almost surely, 2^221091072 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 221091072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295317120).

221091072 is an abundant number, since it is smaller than the sum of its proper divisors (369543168).

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

221091072 is an equidigital number, since it uses as much as digits as its factorization.

221091072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099 (or 1085 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 221091072 is about 14869.1315146514. The cubic root of 221091072 is about 604.6773973928.

The spelling of 221091072 in words is "two hundred twenty-one million, ninety-one thousand, seventy-two".