221223540 has 48 divisors (see below), whose sum is σ = 622036800. Its totient is φ = 58744320.

The previous prime is 221223523. The next prime is 221223547. The reversal of 221223540 is 45322122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221223547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6811 + ... + 22109.

It is an arithmetic number, because the mean of its divisors is an integer number (12959100).

Almost surely, 2^221223540 is an apocalyptic number.

221223540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221223540 is an abundant number, since it is smaller than the sum of its proper divisors (400813260).

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

221223540 is a wasteful number, since it uses less digits than its factorization.

221223540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15552 (or 15550 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 221223540 is about 14873.5853108791. The cubic root of 221223540 is about 604.7981386067.

Adding to 221223540 its reverse (45322122), we get a palindrome (266545662).

It can be divided in two parts, 2212 and 23540, that added together give a palindrome (25752).

The spelling of 221223540 in words is "two hundred twenty-one million, two hundred twenty-three thousand, five hundred forty".