1221144210 has 192 divisors, whose sum is σ = 3755082240. Its totient is φ = 271434240.

The previous prime is 1221144191. The next prime is 1221144217. The reversal of 1221144210 is 124411221.

1221144210 is a `hidden beast` number, since 1 + 2 + 211 + 442 + 10 = 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 (1221144217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3075732 + ... + 3076128.

It is an arithmetic number, because the mean of its divisors is an integer number (19557720).

Almost surely, 2^1221144210 is an apocalyptic number.

1221144210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221144210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1877541120).

1221144210 is an abundant number, since it is smaller than the sum of its proper divisors (2533938030).

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

1221144210 is a wasteful number, since it uses less digits than its factorization.

1221144210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1221144210 is about 34944.8738730017. The cubic root of 1221144210 is about 1068.8636756075.

Adding to 1221144210 its reverse (124411221), we get a palindrome (1345555431).

The spelling of 1221144210 in words is "one billion, two hundred twenty-one million, one hundred forty-four thousand, two hundred ten".