1221055043401 has 4 divisors (see below), whose sum is σ = 1235766550032. Its totient is φ = 1206343536772.

The previous prime is 1221055043389. The next prime is 1221055043419. The reversal of 1221055043401 is 1043405501221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1221055043401 - 2¹⁵ = 1221055010633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221055043401.

It is not an unprimeable number, because it can be changed into a prime (1221055043101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7355753191 + ... + 7355753356.

It is an arithmetic number, because the mean of its divisors is an integer number (308941637508).

Almost surely, 2^{1221055043401} is an apocalyptic number.

It is an amenable number.

1221055043401 is a deficient number, since it is larger than the sum of its proper divisors (14711506631).

1221055043401 is an equidigital number, since it uses as much as digits as its factorization.

1221055043401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14711506630.

The product of its (nonzero) digits is 4800, while the sum is 28.

The spelling of 1221055043401 in words is "one trillion, two hundred twenty-one billion, fifty-five million, forty-three thousand, four hundred one".