221445140 has 24 divisors (see below), whose sum is σ = 531468672. Its totient is φ = 75924000.

The previous prime is 221445109. The next prime is 221445181. The reversal of 221445140 is 41544122.

221445140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 790736 + ... + 791015.

It is an arithmetic number, because the mean of its divisors is an integer number (22144528).

Almost surely, 2^221445140 is an apocalyptic number.

221445140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221445140 is an abundant number, since it is smaller than the sum of its proper divisors (310023532).

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

221445140 is a wasteful number, since it uses less digits than its factorization.

221445140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581767 (or 1581765 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 221445140 is about 14881.0328942584. The cubic root of 221445140 is about 605.0000136603. Note that the first 4 decimals are identical.

Adding to 221445140 its reverse (41544122), we get a palindrome (262989262).

The spelling of 221445140 in words is "two hundred twenty-one million, four hundred forty-five thousand, one hundred forty".