1211111110220 has 24 divisors (see below), whose sum is σ = 2774545453008. Its totient is φ = 440404040000.

The previous prime is 1211111110213. The next prime is 1211111110283. The reversal of 1211111110220 is 220111111121.

It is a junction number, because it is equal to n+sod(n) for n = 1211111110195 and 1211111110204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2752525031 + ... + 2752525470.

It is an arithmetic number, because the mean of its divisors is an integer number (115606060542).

Almost surely, 2^{1211111110220} is an apocalyptic number.

1211111110220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211111110220 is an abundant number, since it is smaller than the sum of its proper divisors (1563434342788).

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

1211111110220 is a wasteful number, since it uses less digits than its factorization.

1211111110220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5505050521 (or 5505050519 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 1211111110220 its reverse (220111111121), we get a palindrome (1431222221341).

Subtracting from 1211111110220 its reverse (220111111121), we obtain a palindrome (990999999099).

The spelling of 1211111110220 in words is "one trillion, two hundred eleven billion, one hundred eleven million, one hundred ten thousand, two hundred twenty".