1591091 has 8 divisors (see below), whose sum is σ = 1646400. Its totient is φ = 1536768.

The previous prime is 1591033. The next prime is 1591097. The reversal of 1591091 is 1901951.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1591091 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1591091.

It is not an unprimeable number, because it can be changed into a prime (1591097) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4385 + ... + 4733.

It is an arithmetic number, because the mean of its divisors is an integer number (205800).

2^1591091 is an apocalyptic number.

1591091 is a deficient number, since it is larger than the sum of its proper divisors (55309).

1591091 is an equidigital number, since it uses as much as digits as its factorization.

1591091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493.

The product of its (nonzero) digits is 405, while the sum is 26.

The square root of 1591091 is about 1261.3845567471. The cubic root of 1591091 is about 116.7432214104.

The spelling of 1591091 in words is "one million, five hundred ninety-one thousand, ninety-one".