221045760 has 440 divisors, whose sum is σ = 873839736. Its totient is φ = 53084160.

The previous prime is 221045731. The next prime is 221045771. The reversal of 221045760 is 67540122.

It can be written as a sum of positive squares in 4 ways, for example, as 5308416 + 215737344 = 2304^2 + 14688^2 .

It is a super-2 number, since 2×221045760² = 97722456027955200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5391340 + ... + 5391380.

Almost surely, 2^221045760 is an apocalyptic number.

221045760 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 221045760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436919868).

221045760 is an abundant number, since it is smaller than the sum of its proper divisors (652793976).

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

221045760 is a wasteful number, since it uses less digits than its factorization.

221045760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 221045760 is about 14867.6077430096. The cubic root of 221045760 is about 604.6360855871.

Adding to 221045760 its reverse (67540122), we get a palindrome (288585882).

The spelling of 221045760 in words is "two hundred twenty-one million, forty-five thousand, seven hundred sixty".