221135616 has 288 divisors, whose sum is σ = 741726720. Its totient is φ = 64475136.

The previous prime is 221135581. The next prime is 221135633. The reversal of 221135616 is 616531122.

221135616 is a `hidden beast` number, since 2 + 2 + 11 + 35 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 221135616.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2066635 + ... + 2066741.

It is an arithmetic number, because the mean of its divisors is an integer number (2575440).

Almost surely, 2^221135616 is an apocalyptic number.

221135616 is a gapful number since it is divisible by the number (26) 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 221135616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (370863360).

221135616 is an abundant number, since it is smaller than the sum of its proper divisors (520591104).

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

221135616 is a wasteful number, since it uses less digits than its factorization.

221135616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 148 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 221135616 is about 14870.6293074638. The cubic root of 221135616 is about 604.7180034970.

Adding to 221135616 its reverse (616531122), we get a palindrome (837666738).

The spelling of 221135616 in words is "two hundred twenty-one million, one hundred thirty-five thousand, six hundred sixteen".