1221001101012 has 192 divisors, whose sum is σ = 3645994641408. Its totient is φ = 308854080000.

The previous prime is 1221001101011. The next prime is 1221001101053. The reversal of 1221001101012 is 2101011001221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001101011) 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, 5585523 + ... + 5800005.

It is an arithmetic number, because the mean of its divisors is an integer number (18989555424).

Almost surely, 2^{1221001101012} is an apocalyptic number.

1221001101012 is a gapful number since it is divisible by the number (12) 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 1221001101012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1822997320704).

1221001101012 is an abundant number, since it is smaller than the sum of its proper divisors (2424993540396).

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

1221001101012 is a wasteful number, since it uses less digits than its factorization.

1221001101012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214670 (or 214668 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221001101012 its reverse (2101011001221), we get a palindrome (3322012102233).

The spelling of 1221001101012 in words is "one trillion, two hundred twenty-one billion, one million, one hundred one thousand, twelve".