1213405 has 4 divisors (see below), whose sum is σ = 1456092. Its totient is φ = 970720.

The previous prime is 1213379. The next prime is 1213427. The reversal of 1213405 is 5043121.

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 887364 + 326041 = 942^2 + 571^2 .

It is not a de Polignac number, because 1213405 - 2¹⁵ = 1180637 is a prime.

It is a Duffinian number.

1213405 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121336 + ... + 121345.

It is an arithmetic number, because the mean of its divisors is an integer number (364023).

2^1213405 is an apocalyptic number.

It is an amenable number.

1213405 is a deficient number, since it is larger than the sum of its proper divisors (242687).

1213405 is an equidigital number, since it uses as much as digits as its factorization.

1213405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242686.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1213405 is about 1101.5466399567. The cubic root of 1213405 is about 106.6600853144.

Adding to 1213405 its reverse (5043121), we get a palindrome (6256526).

The spelling of 1213405 in words is "one million, two hundred thirteen thousand, four hundred five".