421739 has 2 divisors, whose sum is σ = 421740. Its totient is φ = 421738.

The previous prime is 421727. The next prime is 421741. The reversal of 421739 is 937124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 421739 - 2⁸ = 421483 is a prime.

Together with 421741, 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 (421709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210869 + 210870.

It is an arithmetic number, because the mean of its divisors is an integer number (210870).

2⁴²¹⁷³⁹ is an apocalyptic number.

421739 is a deficient number, since it is larger than the sum of its proper divisors (1).

421739 is an equidigital number, since it uses as much as digits as its factorization.

421739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 26.

The square root of 421739 is about 649.4143515507. The cubic root of 421739 is about 74.9919398746.

The spelling of 421739 in words is "four hundred twenty-one thousand, seven hundred thirty-nine".