1221405626443 has 4 divisors (see below), whose sum is σ = 1221408567280. Its totient is φ = 1221402685608.

The previous prime is 1221405626431. The next prime is 1221405626471. The reversal of 1221405626443 is 3446265041221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221405626443 - 2²⁹ = 1220868755531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221405626396 and 1221405626405.

It is not an unprimeable number, because it can be changed into a prime (1221405626423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719655 + ... + 1720672.

It is an arithmetic number, because the mean of its divisors is an integer number (305352141820).

Almost surely, 2^{1221405626443} is an apocalyptic number.

1221405626443 is a deficient number, since it is larger than the sum of its proper divisors (2940837).

1221405626443 is an equidigital number, since it uses as much as digits as its factorization.

1221405626443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2940836.

The product of its (nonzero) digits is 276480, while the sum is 40.

The spelling of 1221405626443 in words is "one trillion, two hundred twenty-one billion, four hundred five million, six hundred twenty-six thousand, four hundred forty-three".