11111221221210 has 96 divisors (see below), whose sum is σ = 31516064349120. Its totient is φ = 2693578060800.

The previous prime is 11111221220951. The next prime is 11111221221259. The reversal of 11111221221210 is 1212212211111.

It is a happy number.

11111221221210 is a `hidden beast` number, since 1 + 1 + 1 + 11 + 221 + 221 + 210 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 91434090 + ... + 91555530.

It is an arithmetic number, because the mean of its divisors is an integer number (328292336970).

Almost surely, 2^{11111221221210} is an apocalyptic number.

11111221221210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

11111221221210 is an abundant number, since it is smaller than the sum of its proper divisors (20404843127910).

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

11111221221210 is a wasteful number, since it uses less digits than its factorization.

11111221221210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213884 (or 213881 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 11111221221210 its reverse (1212212211111), we get a palindrome (12323433432321).

It can be divided in two parts, 1111122 and 1221210, that added together give a palindrome (2332332).

The spelling of 11111221221210 in words is "eleven trillion, one hundred eleven billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred ten".