1221002010000 has 150 divisors (see below), whose sum is σ = 4270020710670. Its totient is φ = 325600512000.

The previous prime is 1221002009971. The next prime is 1221002010001. The reversal of 1221002010000 is 102001221.

It can be written as a sum of positive squares in 5 ways, for example, as 287776456704 + 933225553296 = 536448^2 + 966036^2 .

It is a tau number, because it is divible by the number of its divisors (150).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1221002010001) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 6693345 + ... + 6873344.

Almost surely, 2^{1221002010000} is an apocalyptic number.

1221002010000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221002010000 is an abundant number, since it is smaller than the sum of its proper divisors (3049018700670).

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

1221002010000 is a wasteful number, since it uses less digits than its factorization.

1221002010000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13566723 (or 13566699 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1221002010000 its reverse (102001221), we get a palindrome (1221104011221).

The spelling of 1221002010000 in words is "one trillion, two hundred twenty-one billion, two million, ten thousand".