221151760 has 40 divisors (see below), whose sum is σ = 517656600. Its totient is φ = 87862272.

The previous prime is 221151743. The next prime is 221151769. The reversal of 221151760 is 67151122.

It can be written as a sum of positive squares in 4 ways, for example, as 5531904 + 215619856 = 2352^2 + 14684^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (221151769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2644 + ... + 21196.

It is an arithmetic number, because the mean of its divisors is an integer number (12941415).

Almost surely, 2^221151760 is an apocalyptic number.

221151760 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 221151760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258828300).

221151760 is an abundant number, since it is smaller than the sum of its proper divisors (296504840).

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

221151760 is a wasteful number, since it uses less digits than its factorization.

221151760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18715 (or 18709 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 221151760 is about 14871.1721125135. The cubic root of 221151760 is about 604.7327189464.

The spelling of 221151760 in words is "two hundred twenty-one million, one hundred fifty-one thousand, seven hundred sixty".