1213121221110 has 96 divisors (see below), whose sum is σ = 3429912369312. Its totient is φ = 296240716800.

The previous prime is 1213121221069. The next prime is 1213121221157. The reversal of 1213121221110 is 111221213121.

It is a happy number.

1213121221110 is a `hidden beast` number, since 1 + 21 + 312 + 1 + 221 + 110 = 666.

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

It is a congruent number.

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, 10658116 + ... + 10771335.

It is an arithmetic number, because the mean of its divisors is an integer number (35728253847).

Almost surely, 2^{1213121221110} is an apocalyptic number.

1213121221110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1213121221110 is an abundant number, since it is smaller than the sum of its proper divisors (2216791148202).

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

1213121221110 is a wasteful number, since it uses less digits than its factorization.

1213121221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21429518 (or 21429515 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 1213121221110 its reverse (111221213121), we get a palindrome (1324342434231).

The spelling of 1213121221110 in words is "one trillion, two hundred thirteen billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred ten".