1591001 has 2 divisors, whose sum is σ = 1591002. Its totient is φ = 1591000.

The previous prime is 1590991. The next prime is 1591021. The reversal of 1591001 is 1001951.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 912025 + 678976 = 955^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 1591001 - 2⁶ = 1590937 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1591021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 795500 + 795501.

It is an arithmetic number, because the mean of its divisors is an integer number (795501).

2^1591001 is an apocalyptic number.

It is an amenable number.

1591001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1591001 is an equidigital number, since it uses as much as digits as its factorization.

1591001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45, while the sum is 17.

The square root of 1591001 is about 1261.3488811586. The cubic root of 1591001 is about 116.7410201770.

Adding to 1591001 its reverse (1001951), we get a palindrome (2592952).

The spelling of 1591001 in words is "one million, five hundred ninety-one thousand, one".