1221221122210 has 32 divisors (see below), whose sum is σ = 2207897024112. Its totient is φ = 486333619200.

The previous prime is 1221221122207. The next prime is 1221221122223. The reversal of 1221221122210 is 122211221221.

It can be written as a sum of positive squares in 8 ways, for example, as 817626467529 + 403594654681 = 904227^2 + 635291^2 .

It is an unprimeable number.

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, 23042862 + ... + 23095798.

Almost surely, 2^{1221221122210} is an apocalyptic number.

1221221122210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221221122210 is a deficient number, since it is larger than the sum of its proper divisors (986675901902).

1221221122210 is a wasteful number, since it uses less digits than its factorization.

1221221122210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63078.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1221221122210 its reverse (122211221221), we get a palindrome (1343432343431).

It can be divided in two parts, 1221221 and 122210, that added together give a palindrome (1343431).

The spelling of 1221221122210 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred ten".