1306905 has 16 divisors (see below), whose sum is σ = 2108544. Its totient is φ = 691200.

The previous prime is 1306901. The next prime is 1306913. The reversal of 1306905 is 5096031.

1306905 = 357² + 358² + ... + 366².

It is not a de Polignac number, because 1306905 - 2² = 1306901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1306901) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1977 + ... + 2553.

It is an arithmetic number, because the mean of its divisors is an integer number (131784).

2^1306905 is an apocalyptic number.

1306905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1306905 is a deficient number, since it is larger than the sum of its proper divisors (801639).

1306905 is a wasteful number, since it uses less digits than its factorization.

1306905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736.

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 1306905 is about 1143.1994576626. The cubic root of 1306905 is about 109.3321797006.

It can be divided in two parts, 1306 and 905, that added together give a triangular number (2211 = T₆₆).

The spelling of 1306905 in words is "one million, three hundred six thousand, nine hundred five".