1720427 has 2 divisors, whose sum is σ = 1720428. Its totient is φ = 1720426.

The previous prime is 1720421. The next prime is 1720429. The reversal of 1720427 is 7240271.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1720427 - 2⁶ = 1720363 is a prime.

Together with 1720429, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1720421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860213 + 860214.

It is an arithmetic number, because the mean of its divisors is an integer number (860214).

2^1720427 is an apocalyptic number.

1720427 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720427 is an equidigital number, since it uses as much as digits as its factorization.

1720427 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 1720427 is about 1311.6504869820. The cubic root of 1720427 is about 119.8244423620.

Adding to 1720427 its reverse (7240271), we get a palindrome (8960698).

The spelling of 1720427 in words is "one million, seven hundred twenty thousand, four hundred twenty-seven".