221807712 has 144 divisors (see below), whose sum is σ = 689299632. Its totient is φ = 62254080.

The previous prime is 221807681. The next prime is 221807731. The reversal of 221807712 is 217708122.

It is a happy number.

It is a super-2 number, since 2×221807712² = 98397322205349888, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221807712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 286558 + ... + 287330.

It is an arithmetic number, because the mean of its divisors is an integer number (4786803).

Almost surely, 2^221807712 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 221807712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344649816).

221807712 is an abundant number, since it is smaller than the sum of its proper divisors (467491920).

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

221807712 is a wasteful number, since it uses less digits than its factorization.

221807712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861 (or 846 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 221807712 is about 14893.2102650839. The cubic root of 221807712 is about 605.3300223425.

It can be divided in two parts, 22180 and 7712, that added together give a palindrome (29892).

The spelling of 221807712 in words is "two hundred twenty-one million, eight hundred seven thousand, seven hundred twelve".