1221100220210 has 24 divisors (see below), whose sum is σ = 2380061615940. Its totient is φ = 450867772992.

The previous prime is 1221100220167. The next prime is 1221100220233. The reversal of 1221100220210 is 120220011221.

It can be written as a sum of positive squares in 6 ways, for example, as 5380075801 + 1215720144409 = 73349^2 + 1102597^2 .

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 11 ways as a sum of consecutive naturals, for example, 361270565 + ... + 361273944.

Almost surely, 2^{1221100220210} is an apocalyptic number.

1221100220210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221100220210 is a deficient number, since it is larger than the sum of its proper divisors (1158961395730).

1221100220210 is a wasteful number, since it uses less digits than its factorization.

1221100220210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722544542 (or 722544529 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1221100220210 its reverse (120220011221), we get a palindrome (1341320231431).

The spelling of 1221100220210 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred twenty thousand, two hundred ten".