221568264 has 128 divisors (see below), whose sum is σ = 638668800. Its totient is φ = 71124480.

The previous prime is 221568257. The next prime is 221568283. The reversal of 221568264 is 462865122.

It is a happy number.

221568264 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221568264² = 98184991223947392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1124614 + ... + 1124810.

It is an arithmetic number, because the mean of its divisors is an integer number (4989600).

Almost surely, 2^221568264 is an apocalyptic number.

221568264 is a gapful number since it is divisible by the number (24) 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 221568264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319334400).

221568264 is an abundant number, since it is smaller than the sum of its proper divisors (417100536).

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

221568264 is a wasteful number, since it uses less digits than its factorization.

221568264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380 (or 370 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 221568264 is about 14885.1692633977. The cubic root of 221568264 is about 605.1121200122.

The spelling of 221568264 in words is "two hundred twenty-one million, five hundred sixty-eight thousand, two hundred sixty-four".