1275991 has 4 divisors (see below), whose sum is σ = 1317184. Its totient is φ = 1234800.

The previous prime is 1275979. The next prime is 1276001. The reversal of 1275991 is 1995721.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1275991 - 2⁷ = 1275863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1275931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20550 + ... + 20611.

It is an arithmetic number, because the mean of its divisors is an integer number (329296).

2^1275991 is an apocalyptic number.

1275991 is a deficient number, since it is larger than the sum of its proper divisors (41193).

1275991 is an equidigital number, since it uses as much as digits as its factorization.

1275991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41192.

The product of its digits is 5670, while the sum is 34.

The square root of 1275991 is about 1129.5977160034. The cubic root of 1275991 is about 108.4632309027.

The spelling of 1275991 in words is "one million, two hundred seventy-five thousand, nine hundred ninety-one".