1280091 has 4 divisors (see below), whose sum is σ = 1706792. Its totient is φ = 853392.

The previous prime is 1280023. The next prime is 1280101. The reversal of 1280091 is 1900821.

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

It is a de Polignac number, because none of the positive numbers 2^k-1280091 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280291) 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, 213346 + ... + 213351.

It is an arithmetic number, because the mean of its divisors is an integer number (426698).

2^1280091 is an apocalyptic number.

1280091 is a deficient number, since it is larger than the sum of its proper divisors (426701).

1280091 is an equidigital number, since it uses as much as digits as its factorization.

1280091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426700.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1280091 is about 1131.4110658819. The cubic root of 1280091 is about 108.5792776445.

The spelling of 1280091 in words is "one million, two hundred eighty thousand, ninety-one".