221540672 has 28 divisors (see below), whose sum is σ = 443985396. Its totient is φ = 109670400.

The previous prime is 221540633. The next prime is 221540677. The reversal of 221540672 is 276045122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 207821056 + 13719616 = 14416^2 + 3704^2 .

It is a super-3 number, since 3×221540672³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221540677) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 10673 + ... + 23600.

Almost surely, 2^221540672 is an apocalyptic number.

It is an amenable number.

221540672 is an abundant number, since it is smaller than the sum of its proper divisors (222444724).

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

221540672 is a wasteful number, since it uses less digits than its factorization.

221540672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34386 (or 34376 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 221540672 is about 14884.2424059809. The cubic root of 221540672 is about 605.0870006706.

Adding to 221540672 its reverse (276045122), we get a palindrome (497585794).

The spelling of 221540672 in words is "two hundred twenty-one million, five hundred forty thousand, six hundred seventy-two".