1221100121210 has 16 divisors (see below), whose sum is σ = 2219742400392. Its totient is φ = 483604008000.

The previous prime is 1221100121203. The next prime is 1221100121261. The reversal of 1221100121210 is 121210011221.

It can be written as a sum of positive squares in 4 ways, for example, as 1165413088849 + 55687032361 = 1079543^2 + 235981^2 .

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, 604504001 + ... + 604506020.

Almost surely, 2^{1221100121210} is an apocalyptic number.

1221100121210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221100121210 is a deficient number, since it is larger than the sum of its proper divisors (998642279182).

1221100121210 is a wasteful number, since it uses less digits than its factorization.

1221100121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1209010129.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221100121210 its reverse (121210011221), we get a palindrome (1342310132431).

The spelling of 1221100121210 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred twenty-one thousand, two hundred ten".