221738216 has 32 divisors (see below), whose sum is σ = 495815040. Its totient is φ = 90898368.

The previous prime is 221738207. The next prime is 221738261. The reversal of 221738216 is 612837122.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84791 + ... + 87366.

It is an arithmetic number, because the mean of its divisors is an integer number (15494220).

Almost surely, 2^221738216 is an apocalyptic number.

It is an amenable number.

221738216 is an abundant number, since it is smaller than the sum of its proper divisors (274076824).

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

221738216 is a wasteful number, since it uses less digits than its factorization.

221738216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172193 (or 172189 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 221738216 is about 14890.8769385822. The cubic root of 221738216 is about 605.2667957920.

The spelling of 221738216 in words is "two hundred twenty-one million, seven hundred thirty-eight thousand, two hundred sixteen".