221236240 has 20 divisors (see below), whose sum is σ = 514374444. Its totient is φ = 88494464.

The previous prime is 221236237. The next prime is 221236277. The reversal of 221236240 is 42632122.

It can be written as a sum of positive squares in 2 ways, for example, as 36385024 + 184851216 = 6032^2 + 13596^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1382647 + ... + 1382806.

Almost surely, 2^221236240 is an apocalyptic number.

221236240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221236240 is an abundant number, since it is smaller than the sum of its proper divisors (293138204).

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

221236240 is a wasteful number, since it uses less digits than its factorization.

221236240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2765466 (or 2765460 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 221236240 is about 14874.0122361117. The cubic root of 221236240 is about 604.8097118015.

Adding to 221236240 its reverse (42632122), we get a palindrome (263868362).

The spelling of 221236240 in words is "two hundred twenty-one million, two hundred thirty-six thousand, two hundred forty".