1221101112210 has 64 divisors (see below), whose sum is σ = 3525585177600. Its totient is φ = 264418886592.

The previous prime is 1221101112151. The next prime is 1221101112211. The reversal of 1221101112210 is 122111011221.

It is a happy number.

It is a super-2 number, since 2×1221101112210² (a number of 25 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1221101112210.

It is not an unprimeable number, because it can be changed into a prime (1221101112211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153016200 + ... + 153024179.

It is an arithmetic number, because the mean of its divisors is an integer number (55087268400).

Almost surely, 2^{1221101112210} is an apocalyptic number.

1221101112210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221101112210 is an abundant number, since it is smaller than the sum of its proper divisors (2304484065390).

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

1221101112210 is a wasteful number, since it uses less digits than its factorization.

1221101112210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306040415.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221101112210 its reverse (122111011221), we get a palindrome (1343212123431).

The spelling of 1221101112210 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred twelve thousand, two hundred ten".