1221221102010 has 128 divisors (see below), whose sum is σ = 3704794136064. Its totient is φ = 250700313600.

The previous prime is 1221221101873. The next prime is 1221221102011. The reversal of 1221221102010 is 102011221221.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (1221221102011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5944041 + ... + 6146060.

It is an arithmetic number, because the mean of its divisors is an integer number (28943704188).

Almost surely, 2^{1221221102010} is an apocalyptic number.

1221221102010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221221102010 is an abundant number, since it is smaller than the sum of its proper divisors (2483573034054).

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

1221221102010 is a wasteful number, since it uses less digits than its factorization.

1221221102010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12090168.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221221102010 its reverse (102011221221), we get a palindrome (1323232323231).

It can be divided in two parts, 1221221 and 102010, that added together give a palindrome (1323231).

The spelling of 1221221102010 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred two thousand, ten".