221622720 has 224 divisors, whose sum is σ = 793552896. Its totient is φ = 51916800.

The previous prime is 221622701. The next prime is 221622721. The reversal of 221622720 is 27226122.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221622721) 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 31 ways as a sum of consecutive naturals, for example, 327022 + ... + 327698.

Almost surely, 2^221622720 is an apocalyptic number.

221622720 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 221622720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (396776448).

221622720 is an abundant number, since it is smaller than the sum of its proper divisors (571930176).

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

221622720 is a wasteful number, since it uses less digits than its factorization.

221622720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739 (or 729 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 221622720 is about 14886.9983542687. The cubic root of 221622720 is about 605.1616898164.

Adding to 221622720 its reverse (27226122), we get a palindrome (248848842).

The spelling of 221622720 in words is "two hundred twenty-one million, six hundred twenty-two thousand, seven hundred twenty".