1291405 has 8 divisors (see below), whose sum is σ = 1640952. Its totient is φ = 972288.

The previous prime is 1291391. The next prime is 1291421. The reversal of 1291405 is 5041921.

It can be written as a sum of positive squares in 4 ways, for example, as 660969 + 630436 = 813^2 + 794^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1291405 - 2¹⁵ = 1258637 is a prime.

It is a Duffinian 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 7 ways as a sum of consecutive naturals, for example, 7512 + ... + 7681.

It is an arithmetic number, because the mean of its divisors is an integer number (205119).

2^1291405 is an apocalyptic number.

It is an amenable number.

1291405 is a deficient number, since it is larger than the sum of its proper divisors (349547).

1291405 is a wasteful number, since it uses less digits than its factorization.

1291405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15215.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1291405 is about 1136.4000175994. The cubic root of 1291405 is about 108.8982300669.

The spelling of 1291405 in words is "one million, two hundred ninety-one thousand, four hundred five".