1205404020543 has 4 divisors (see below), whose sum is σ = 1607205360728. Its totient is φ = 803602680360.

The previous prime is 1205404020523. The next prime is 1205404020547. The reversal of 1205404020543 is 3450204045021.

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

It is not a de Polignac number, because 1205404020543 - 2⁸ = 1205404020287 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 1205404020543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205404020547) 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, 200900670088 + ... + 200900670093.

It is an arithmetic number, because the mean of its divisors is an integer number (401801340182).

Almost surely, 2^{1205404020543} is an apocalyptic number.

1205404020543 is a deficient number, since it is larger than the sum of its proper divisors (401801340185).

1205404020543 is an equidigital number, since it uses as much as digits as its factorization.

1205404020543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401801340184.

The product of its (nonzero) digits is 19200, while the sum is 30.

Adding to 1205404020543 its reverse (3450204045021), we get a palindrome (4655608065564).

The spelling of 1205404020543 in words is "one trillion, two hundred five billion, four hundred four million, twenty thousand, five hundred forty-three".