421022009 has 2 divisors, whose sum is σ = 421022010. Its totient is φ = 421022008.

The previous prime is 421021963. The next prime is 421022011. The reversal of 421022009 is 900220124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 271326784 + 149695225 = 16472^2 + 12235^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421022009 is a prime.

Together with 421022011, 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 (421022309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210511004 + 210511005.

It is an arithmetic number, because the mean of its divisors is an integer number (210511005).

Almost surely, 2^421022009 is an apocalyptic number.

It is an amenable number.

421022009 is a deficient number, since it is larger than the sum of its proper divisors (1).

421022009 is an equidigital number, since it uses as much as digits as its factorization.

421022009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 421022009 is about 20518.8208481872. The cubic root of 421022009 is about 749.4941827938.

The spelling of 421022009 in words is "four hundred twenty-one million, twenty-two thousand, nine".