1211221001320 has 96 divisors (see below), whose sum is σ = 3052039593960. Its totient is φ = 432133644800.

The previous prime is 1211221001239. The next prime is 1211221001321. The reversal of 1211221001320 is 231001221121.

It can be written as a sum of positive squares in 4 ways, for example, as 1177741516644 + 33479484676 = 1085238^2 + 182974^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1211221001294 and 1211221001303.

It is not an unprimeable number, because it can be changed into a prime (1211221001321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2104351 + ... + 2617390.

Almost surely, 2^{1211221001320} is an apocalyptic number.

1211221001320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211221001320 is an abundant number, since it is smaller than the sum of its proper divisors (1840818592640).

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

1211221001320 is a wasteful number, since it uses less digits than its factorization.

1211221001320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4721827 (or 4721812 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 1211221001320 its reverse (231001221121), we get a palindrome (1442222222441).

The spelling of 1211221001320 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one thousand, three hundred twenty".