1211021211220 has 48 divisors (see below), whose sum is σ = 2666293112448. Its totient is φ = 461151250560.

The previous prime is 1211021211209. The next prime is 1211021211251. The reversal of 1211021211220 is 221121201121.

It is a junction number, because it is equal to n+sod(n) for n = 1211021211194 and 1211021211203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6141459 + ... + 6335578.

It is an arithmetic number, because the mean of its divisors is an integer number (55547773176).

Almost surely, 2^{1211021211220} is an apocalyptic number.

1211021211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211021211220 is an abundant number, since it is smaller than the sum of its proper divisors (1455271901228).

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

1211021211220 is a wasteful number, since it uses less digits than its factorization.

1211021211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12477280 (or 12477278 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211021211220 its reverse (221121201121), we get a palindrome (1432142412341).

It can be divided in two parts, 1211021 and 211220, that added together give a palindrome (1422241).

The spelling of 1211021211220 in words is "one trillion, two hundred eleven billion, twenty-one million, two hundred eleven thousand, two hundred twenty".