221427936 has 72 divisors (see below), whose sum is σ = 631776600. Its totient is φ = 73564416.

The previous prime is 221427931. The next prime is 221427937. The reversal of 221427936 is 639724122.

221427936 is a `hidden beast` number, since 221 + 427 + 9 + 3 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a self number, because there is not a number n which added to its sum of digits gives 221427936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221427931) 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 11 ways as a sum of consecutive naturals, for example, 99411 + ... + 101613.

It is an arithmetic number, because the mean of its divisors is an integer number (8774675).

Almost surely, 2^221427936 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 221427936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315888300).

221427936 is an abundant number, since it is smaller than the sum of its proper divisors (410348664).

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

221427936 is a wasteful number, since it uses less digits than its factorization.

221427936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2568 (or 2557 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 221427936 is about 14880.4548317583. The cubic root of 221427936 is about 604.9843458372.

The spelling of 221427936 in words is "two hundred twenty-one million, four hundred twenty-seven thousand, nine hundred thirty-six".