1221103045421 has 16 divisors (see below), whose sum is σ = 1396314955776. Its totient is φ = 1046083495536.

The previous prime is 1221103045391. The next prime is 1221103045427. The reversal of 1221103045421 is 1245403011221.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1221103045421 - 2²⁶ = 1221035936557 is a prime.

It is a super-3 number, since 3×1221103045421³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221103045427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175266080 + ... + 175273046.

It is an arithmetic number, because the mean of its divisors is an integer number (87269684736).

Almost surely, 2^{1221103045421} is an apocalyptic number.

It is an amenable number.

1221103045421 is a deficient number, since it is larger than the sum of its proper divisors (175211910355).

1221103045421 is an equidigital number, since it uses as much as digits as its factorization.

1221103045421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17168.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 1221103045421 its reverse (1245403011221), we get a palindrome (2466506056642).

The spelling of 1221103045421 in words is "one trillion, two hundred twenty-one billion, one hundred three million, forty-five thousand, four hundred twenty-one".