1921307 has 2 divisors, whose sum is σ = 1921308. Its totient is φ = 1921306.

The previous prime is 1921277. The next prime is 1921319. The reversal of 1921307 is 7031291.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1921307 - 2¹⁰ = 1920283 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1921327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960653 + 960654.

It is an arithmetic number, because the mean of its divisors is an integer number (960654).

2^1921307 is an apocalyptic number.

1921307 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921307 is an equidigital number, since it uses as much as digits as its factorization.

1921307 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 1921307 is about 1386.1121888217. The cubic root of 1921307 is about 124.3174962918.

Adding to 1921307 its reverse (7031291), we get a palindrome (8952598).

The spelling of 1921307 in words is "one million, nine hundred twenty-one thousand, three hundred seven".