221938308 has 72 divisors (see below), whose sum is σ = 577152576. Its totient is φ = 71870400.

The previous prime is 221938291. The next prime is 221938319. The reversal of 221938308 is 803839122.

It is a happy number.

It is a super-2 number, since 2×221938308² = 98513225115805728, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 481198 + ... + 481658.

It is an arithmetic number, because the mean of its divisors is an integer number (8016008).

Almost surely, 2^221938308 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 221938308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288576288).

221938308 is an abundant number, since it is smaller than the sum of its proper divisors (355214268).

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

221938308 is a wasteful number, since it uses less digits than its factorization.

221938308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825 (or 820 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 221938308 is about 14897.5940339372. The cubic root of 221938308 is about 605.4488011546.

The spelling of 221938308 in words is "two hundred twenty-one million, nine hundred thirty-eight thousand, three hundred eight".