1211321311200 has 864 divisors, whose sum is σ = 5735089930752. Its totient is φ = 232339968000.

The previous prime is 1211321311183. The next prime is 1211321311219. The reversal of 1211321311200 is 21131231121.

1211321311200 is a `hidden beast` number, since 1 + 2 + 11 + 321 + 311 + 20 + 0 = 666.

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 143 ways as a sum of consecutive naturals, for example, 7123165 + ... + 7291235.

It is an arithmetic number, because the mean of its divisors is an integer number (6637835568).

Almost surely, 2^{1211321311200} is an apocalyptic number.

1211321311200 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 1211321311200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2867544965376).

1211321311200 is an abundant number, since it is smaller than the sum of its proper divisors (4523768619552).

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

1211321311200 is a wasteful number, since it uses less digits than its factorization.

1211321311200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168128 (or 168112 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1211321311200 its reverse (21131231121), we get a palindrome (1232452542321).

The spelling of 1211321311200 in words is "one trillion, two hundred eleven billion, three hundred twenty-one million, three hundred eleven thousand, two hundred".