1291605 has 16 divisors (see below), whose sum is σ = 2361984. Its totient is φ = 590400.

The previous prime is 1291603. The next prime is 1291637. The reversal of 1291605 is 5061921.

It is not a de Polignac number, because 1291605 - 2¹ = 1291603 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6046 + ... + 6255.

It is an arithmetic number, because the mean of its divisors is an integer number (147624).

2^1291605 is an apocalyptic number.

1291605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1291605 is a deficient number, since it is larger than the sum of its proper divisors (1070379).

1291605 is a wasteful number, since it uses less digits than its factorization.

1291605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12316.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 1291605 is about 1136.4880113754. The cubic root of 1291605 is about 108.9038514694.

The spelling of 1291605 in words is "one million, two hundred ninety-one thousand, six hundred five".