1491001 has 2 divisors, whose sum is σ = 1491002. Its totient is φ = 1491000.

The previous prime is 1490999. The next prime is 1491013. The reversal of 1491001 is 1001941.

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., 1488400 + 2601 = 1220^2 + 51^2 .

It is an emirp because it is prime and its reverse (1001941) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1491001 - 2¹ = 1490999 is a prime.

Together with 1490999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1491031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745500 + 745501.

It is an arithmetic number, because the mean of its divisors is an integer number (745501).

2^1491001 is an apocalyptic number.

It is an amenable number.

1491001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491001 is an equidigital number, since it uses as much as digits as its factorization.

1491001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1491001 is about 1221.0655183077. The cubic root of 1491001 is about 114.2420475291.

Adding to 1491001 its reverse (1001941), we get a palindrome (2492942).

The spelling of 1491001 in words is "one million, four hundred ninety-one thousand, one".