1648391 has 2 divisors, whose sum is σ = 1648392. Its totient is φ = 1648390.

The previous prime is 1648379. The next prime is 1648417. The reversal of 1648391 is 1938461.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1648391 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1648291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824195 + 824196.

It is an arithmetic number, because the mean of its divisors is an integer number (824196).

2^1648391 is an apocalyptic number.

1648391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1648391 is an equidigital number, since it uses as much as digits as its factorization.

1648391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 1648391 is about 1283.8968027065. The cubic root of 1648391 is about 118.1281524499.

The spelling of 1648391 in words is "one million, six hundred forty-eight thousand, three hundred ninety-one".