221111010 has 72 divisors (see below), whose sum is σ = 610766676. Its totient is φ = 55488000.

The previous prime is 221110997. The next prime is 221111021. The reversal of 221111010 is 10111122.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 105698961 + 115412049 = 10281^2 + 10743^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221110983 and 221111001.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 21760 + ... + 30260.

Almost surely, 2^221111010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221111010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305383338).

221111010 is an abundant number, since it is smaller than the sum of its proper divisors (389655666).

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

221111010 is a wasteful number, since it uses less digits than its factorization.

221111010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8548 (or 8528 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 221111010 is about 14869.8019489165. The cubic root of 221111010 is about 604.6955734555.

Adding to 221111010 its reverse (10111122), we get a palindrome (231222132).

The spelling of 221111010 in words is "two hundred twenty-one million, one hundred eleven thousand, ten".