221205140 has 48 divisors (see below), whose sum is σ = 501578112. Its totient is φ = 81461376.

The previous prime is 221205137. The next prime is 221205143. The reversal of 221205140 is 41502122.

221205140 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221205137) and next prime (221205143).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221205143) 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, 125747 + ... + 127493.

It is an arithmetic number, because the mean of its divisors is an integer number (10449544).

Almost surely, 2^221205140 is an apocalyptic number.

221205140 is a gapful number since it is divisible by the number (20) 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 221205140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250789056).

221205140 is an abundant number, since it is smaller than the sum of its proper divisors (280372972).

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

221205140 is a wasteful number, since it uses less digits than its factorization.

221205140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2256 (or 2254 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 221205140 is about 14872.9667517950. The cubic root of 221205140 is about 604.7813703576.

Adding to 221205140 its reverse (41502122), we get a palindrome (262707262).

The spelling of 221205140 in words is "two hundred twenty-one million, two hundred five thousand, one hundred forty".