1745921 has 2 divisors, whose sum is σ = 1745922. Its totient is φ = 1745920.

The previous prime is 1745911. The next prime is 1745923. The reversal of 1745921 is 1295471.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1597696 + 148225 = 1264^2 + 385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1745921 is a prime.

It is a Sophie Germain prime.

Together with 1745923, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1745923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 872960 + 872961.

It is an arithmetic number, because the mean of its divisors is an integer number (872961).

2^1745921 is an apocalyptic number.

It is an amenable number.

1745921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1745921 is an equidigital number, since it uses as much as digits as its factorization.

1745921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 29.

The square root of 1745921 is about 1321.3330390178. Note that the first 3 decimals coincide. The cubic root of 1745921 is about 120.4134120812.

The spelling of 1745921 in words is "one million, seven hundred forty-five thousand, nine hundred twenty-one".