1291205 has 4 divisors (see below), whose sum is σ = 1549452. Its totient is φ = 1032960.

The previous prime is 1291193. The next prime is 1291211. The reversal of 1291205 is 5021921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5021921 = 227 ⋅22123.

It can be written as a sum of positive squares in 2 ways, for example, as 889249 + 401956 = 943^2 + 634^2 .

It is not a de Polignac number, because 1291205 - 2¹² = 1287109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129116 + ... + 129125.

It is an arithmetic number, because the mean of its divisors is an integer number (387363).

2^1291205 is an apocalyptic number.

It is an amenable number.

1291205 is a deficient number, since it is larger than the sum of its proper divisors (258247).

1291205 is an equidigital number, since it uses as much as digits as its factorization.

1291205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258246.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 1291205 is about 1136.3120170094. The cubic root of 1291205 is about 108.8926080841.

It can be divided in two parts, 12 and 91205, that multiplied together give a triangular number (1094460 = T₁₄₇₉).

The spelling of 1291205 in words is "one million, two hundred ninety-one thousand, two hundred five".