1221010811208 has 48 divisors (see below), whose sum is σ = 3352204353420. Its totient is φ = 401428210176.

The previous prime is 1221010811203. The next prime is 1221010811221. The reversal of 1221010811208 is 8021180101221.

It can be written as a sum of positive squares in 2 ways, for example, as 1217054652804 + 3956158404 = 1103202^2 + 62898^2 .

It is not an unprimeable number, because it can be changed into a prime (1221010811203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 116148741 + ... + 116159252.

Almost surely, 2^{1221010811208} is an apocalyptic number.

1221010811208 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1221010811208 is an abundant number, since it is smaller than the sum of its proper divisors (2131193542212).

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

1221010811208 is a wasteful number, since it uses less digits than its factorization.

1221010811208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232308078 (or 232308071 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

Adding to 1221010811208 its reverse (8021180101221), we get a palindrome (9242190912429).

The spelling of 1221010811208 in words is "one trillion, two hundred twenty-one billion, ten million, eight hundred eleven thousand, two hundred eight".