221115312 has 320 divisors, whose sum is σ = 761856000. Its totient is φ = 60652800.

The previous prime is 221115289. The next prime is 221115319. The reversal of 221115312 is 213511122.

221115312 is a `hidden beast` number, since 22 + 111 + 531 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (221115319) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2798889 + ... + 2798967.

It is an arithmetic number, because the mean of its divisors is an integer number (2380800).

Almost surely, 2^221115312 is an apocalyptic number.

221115312 is a gapful number since it is divisible by the number (22) 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 221115312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (380928000).

221115312 is an abundant number, since it is smaller than the sum of its proper divisors (540740688).

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

221115312 is a wasteful number, since it uses less digits than its factorization.

221115312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 145 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 221115312 is about 14869.9466038046. The cubic root of 221115312 is about 604.6994951409.

Adding to 221115312 its reverse (213511122), we get a palindrome (434626434).

The spelling of 221115312 in words is "two hundred twenty-one million, one hundred fifteen thousand, three hundred twelve".