1221010110 has 96 divisors (see below), whose sum is σ = 3354492960. Its totient is φ = 307286784.

The previous prime is 1221010103. The next prime is 1221010111. The reversal of 1221010110 is 110101221.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 1221010092 and 1221010101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221010111) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 499812 + ... + 502248.

It is an arithmetic number, because the mean of its divisors is an integer number (34942635).

Almost surely, 2^1221010110 is an apocalyptic number.

1221010110 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 1221010110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1677246480).

1221010110 is an abundant number, since it is smaller than the sum of its proper divisors (2133482850).

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

1221010110 is a wasteful number, since it uses less digits than its factorization.

1221010110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2762 (or 2759 counting only the distinct ones).

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

The square root of 1221010110 is about 34942.9550839651. The cubic root of 1221010110 is about 1068.8245484061.

Adding to 1221010110 its reverse (110101221), we get a palindrome (1331111331).

The spelling of 1221010110 in words is "one billion, two hundred twenty-one million, ten thousand, one hundred ten".