1221100202121 has 8 divisors (see below), whose sum is σ = 1628467461504. Its totient is φ = 813899872080.

The previous prime is 1221100202093. The next prime is 1221100202149. The reversal of 1221100202121 is 1212020011221.

It is an interprime number because it is at equal distance from previous prime (1221100202093) and next prime (1221100202149).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221100202121 - 2⁹ = 1221100201609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221100202121.

It is not an unprimeable number, because it can be changed into a prime (1221100402121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41715265 + ... + 41744526.

It is an arithmetic number, because the mean of its divisors is an integer number (203558432688).

Almost surely, 2^{1221100202121} is an apocalyptic number.

It is an amenable number.

1221100202121 is a deficient number, since it is larger than the sum of its proper divisors (407367259383).

1221100202121 is an equidigital number, since it uses as much as digits as its factorization.

1221100202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83464671.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221100202121 its reverse (1212020011221), we get a palindrome (2433120213342).

The spelling of 1221100202121 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred two thousand, one hundred twenty-one".