221664160 has 24 divisors (see below), whose sum is σ = 523681956. Its totient is φ = 88665600.

The previous prime is 221664119. The next prime is 221664161. The reversal of 221664160 is 61466122.

It can be written as a sum of positive squares in 2 ways, for example, as 188348176 + 33315984 = 13724^2 + 5772^2 .

It is not an unprimeable number, because it can be changed into a prime (221664161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 692541 + ... + 692860.

Almost surely, 2^221664160 is an apocalyptic number.

221664160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221664160 is an abundant number, since it is smaller than the sum of its proper divisors (302017796).

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

221664160 is a wasteful number, since it uses less digits than its factorization.

221664160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385416 (or 1385408 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 221664160 is about 14888.3901077316. The cubic root of 221664160 is about 605.1994060721.

The spelling of 221664160 in words is "two hundred twenty-one million, six hundred sixty-four thousand, one hundred sixty".