1205400423 has 4 divisors (see below), whose sum is σ = 1607200568. Its totient is φ = 803600280.

The previous prime is 1205400421. The next prime is 1205400431. The reversal of 1205400423 is 3240045021.

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

It is not a de Polignac number, because 1205400423 - 2¹ = 1205400421 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 1205400423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205400421) 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, 200900068 + ... + 200900073.

It is an arithmetic number, because the mean of its divisors is an integer number (401800142).

Almost surely, 2^1205400423 is an apocalyptic number.

1205400423 is a deficient number, since it is larger than the sum of its proper divisors (401800145).

1205400423 is an equidigital number, since it uses as much as digits as its factorization.

1205400423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401800144.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 1205400423 is about 34718.8770411717. The cubic root of 1205400423 is about 1064.2502965034.

Adding to 1205400423 its reverse (3240045021), we get a palindrome (4445445444).

The spelling of 1205400423 in words is "one billion, two hundred five million, four hundred thousand, four hundred twenty-three".