1205402405 has 4 divisors (see below), whose sum is σ = 1446482892. Its totient is φ = 964321920.

The previous prime is 1205402381. The next prime is 1205402411. The reversal of 1205402405 is 5042045021.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 645464836 + 559937569 = 25406^2 + 23663^2 .

It is not a de Polignac number, because 1205402405 - 2¹⁰ = 1205401381 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120540236 + ... + 120540245.

It is an arithmetic number, because the mean of its divisors is an integer number (361620723).

Almost surely, 2^1205402405 is an apocalyptic number.

It is an amenable number.

1205402405 is a deficient number, since it is larger than the sum of its proper divisors (241080487).

1205402405 is an equidigital number, since it uses as much as digits as its factorization.

1205402405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241080486.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 1205402405 is about 34718.9055847099. The cubic root of 1205402405 is about 1064.2508798069.

Adding to 1205402405 its reverse (5042045021), we get a palindrome (6247447426).

The spelling of 1205402405 in words is "one billion, two hundred five million, four hundred two thousand, four hundred five".