1231405 has 16 divisors (see below), whose sum is σ = 1707264. Its totient is φ = 835200.

The previous prime is 1231387. The next prime is 1231411. The reversal of 1231405 is 5041321.

It is not a de Polignac number, because 1231405 - 2⁷ = 1231277 is a prime.

It is a Duffinian number.

1231405 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5169 + ... + 5401.

It is an arithmetic number, because the mean of its divisors is an integer number (106704).

2^1231405 is an apocalyptic number.

It is an amenable number.

1231405 is a deficient number, since it is larger than the sum of its proper divisors (475859).

1231405 is a wasteful number, since it uses less digits than its factorization.

1231405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396.

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

The square root of 1231405 is about 1109.6868927765. The cubic root of 1231405 is about 107.1849075155.

Adding to 1231405 its reverse (5041321), we get a palindrome (6272726).

The spelling of 1231405 in words is "one million, two hundred thirty-one thousand, four hundred five".