421987 has 2 divisors, whose sum is σ = 421988. Its totient is φ = 421986.

The previous prime is 421973. The next prime is 421997. The reversal of 421987 is 789124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 421987 - 2¹⁵ = 389219 is a prime.

It is a Chen prime.

It is a zygodrome in base 2.

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, 210993 + 210994.

It is an arithmetic number, because the mean of its divisors is an integer number (210994).

2⁴²¹⁹⁸⁷ is an apocalyptic number.

421987 is a deficient number, since it is larger than the sum of its proper divisors (1).

421987 is an equidigital number, since it uses as much as digits as its factorization.

421987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 31.

The square root of 421987 is about 649.6052647570. The cubic root of 421987 is about 75.0066364498.

The spelling of 421987 in words is "four hundred twenty-one thousand, nine hundred eighty-seven".