1211312211220 has 48 divisors (see below), whose sum is σ = 2554885943568. Its totient is φ = 482409354240.

The previous prime is 1211312211203. The next prime is 1211312211223. The reversal of 1211312211220 is 221122131121.

It can be written as a sum of positive squares in 8 ways, for example, as 39995200144 + 1171317011076 = 199988^2 + 1082274^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211312211223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4154544 + ... + 4436536.

It is an arithmetic number, because the mean of its divisors is an integer number (53226790491).

Almost surely, 2^{1211312211220} is an apocalyptic number.

1211312211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211312211220 is an abundant number, since it is smaller than the sum of its proper divisors (1343573732348).

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

1211312211220 is a wasteful number, since it uses less digits than its factorization.

1211312211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282940 (or 282938 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 1211312211220 its reverse (221122131121), we get a palindrome (1432434342341).

The spelling of 1211312211220 in words is "one trillion, two hundred eleven billion, three hundred twelve million, two hundred eleven thousand, two hundred twenty".