221012240 has 80 divisors (see below), whose sum is σ = 549808560. Its totient is φ = 82329600.

The previous prime is 221012227. The next prime is 221012249. The reversal of 221012240 is 42210122.

It can be written as a sum of positive squares in 8 ways, for example, as 89038096 + 131974144 = 9436^2 + 11488^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (221012249) 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, 136556 + ... + 138164.

It is an arithmetic number, because the mean of its divisors is an integer number (6872607).

Almost surely, 2^221012240 is an apocalyptic number.

221012240 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 221012240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274904280).

221012240 is an abundant number, since it is smaller than the sum of its proper divisors (328796320).

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

221012240 is a wasteful number, since it uses less digits than its factorization.

221012240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740 (or 1734 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 221012240 is about 14866.4804173685. The cubic root of 221012240 is about 604.6055211372.

Adding to 221012240 its reverse (42210122), we get a palindrome (263222362).

The spelling of 221012240 in words is "two hundred twenty-one million, twelve thousand, two hundred forty".