421997 has 2 divisors, whose sum is σ = 421998. Its totient is φ = 421996.

The previous prime is 421987. The next prime is 422029. The reversal of 421997 is 799124.

It is an a-pointer prime, because the next prime (422029) can be obtained adding 421997 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 346921 + 75076 = 589^2 + 274^2 .

421997 is a truncatable prime.

It is a cyclic number.

It is not a de Polignac number, because 421997 - 2⁸ = 421741 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 (421907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210998 + 210999.

It is an arithmetic number, because the mean of its divisors is an integer number (210999).

2⁴²¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

421997 is a deficient number, since it is larger than the sum of its proper divisors (1).

421997 is an equidigital number, since it uses as much as digits as its factorization.

421997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 32.

The square root of 421997 is about 649.6129616933. The cubic root of 421997 is about 75.0072289328.

The spelling of 421997 in words is "four hundred twenty-one thousand, nine hundred ninety-seven".