221620140 has 108 divisors (see below), whose sum is σ = 782033616. Its totient is φ = 50654016.

The previous prime is 221620099. The next prime is 221620141. The reversal of 221620140 is 41026122.

221620140 is a `hidden beast` number, since 2 + 2 + 1 + 620 + 1 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (221620141) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3744 + ... + 21383.

It is an arithmetic number, because the mean of its divisors is an integer number (7241052).

Almost surely, 2^221620140 is an apocalyptic number.

221620140 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 221620140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391016808).

221620140 is an abundant number, since it is smaller than the sum of its proper divisors (560413476).

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

221620140 is a wasteful number, since it uses less digits than its factorization.

221620140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25156 (or 25144 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 221620140 is about 14886.9117012227. The cubic root of 221620140 is about 605.1593414964.

Adding to 221620140 its reverse (41026122), we get a palindrome (262646262).

The spelling of 221620140 in words is "two hundred twenty-one million, six hundred twenty thousand, one hundred forty".