221582916 has 72 divisors (see below), whose sum is σ = 581538048. Its totient is φ = 71064000.

The previous prime is 221582909. The next prime is 221582917. The reversal of 221582916 is 619285122.

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

It is not an unprimeable number, because it can be changed into a prime (221582917) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 235006 + ... + 235946.

Almost surely, 2^221582916 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 221582916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290769024).

221582916 is an abundant number, since it is smaller than the sum of its proper divisors (359955132).

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

221582916 is a wasteful number, since it uses less digits than its factorization.

221582916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193 (or 1188 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 221582916 is about 14885.6614229936. The cubic root of 221582916 is about 605.1254581248.

The spelling of 221582916 in words is "two hundred twenty-one million, five hundred eighty-two thousand, nine hundred sixteen".