1221331212000 has 144 divisors (see below), whose sum is σ = 4334504599152. Its totient is φ = 325688313600.

The previous prime is 1221331211999. The next prime is 1221331212029. The reversal of 1221331212000 is 2121331221.

1221331212000 is a `hidden beast` number, since 122 + 1 + 331 + 212 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16926934 + ... + 16998933.

It is an arithmetic number, because the mean of its divisors is an integer number (30100726383).

Almost surely, 2^{1221331212000} is an apocalyptic number.

1221331212000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221331212000 is an abundant number, since it is smaller than the sum of its proper divisors (3113173387152).

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

1221331212000 is a wasteful number, since it uses less digits than its factorization.

1221331212000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33925898 (or 33925877 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 1221331212000 its reverse (2121331221), we get a palindrome (1223452543221).

The spelling of 1221331212000 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, two hundred twelve thousand".