1221212222000 has 80 divisors (see below), whose sum is σ = 2955206092800. Its totient is φ = 488101939200.

The previous prime is 1221212221981. The next prime is 1221212222117. The reversal of 1221212222000 is 2222121221.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 1221212222000.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2319296 + ... + 2796704.

It is an arithmetic number, because the mean of its divisors is an integer number (36940076160).

Almost surely, 2^{1221212222000} is an apocalyptic number.

1221212222000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221212222000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1477603046400).

1221212222000 is an abundant number, since it is smaller than the sum of its proper divisors (1733993870800).

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

1221212222000 is a wasteful number, since it uses less digits than its factorization.

1221212222000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478711 (or 478695 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 1221212222000 its reverse (2222121221), we get a palindrome (1223434343221).

The spelling of 1221212222000 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty-two thousand".