420403409 has 2 divisors, whose sum is σ = 420403410. Its totient is φ = 420403408.

The previous prime is 420403393. The next prime is 420403411. The reversal of 420403409 is 904304024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 259113409 + 161290000 = 16097^2 + 12700^2 .

It is a cyclic number.

It is not a de Polignac number, because 420403409 - 2⁴ = 420403393 is a prime.

Together with 420403411, 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 (420403429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210201704 + 210201705.

It is an arithmetic number, because the mean of its divisors is an integer number (210201705).

Almost surely, 2^420403409 is an apocalyptic number.

It is an amenable number.

420403409 is a deficient number, since it is larger than the sum of its proper divisors (1).

420403409 is an equidigital number, since it uses as much as digits as its factorization.

420403409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 420403409 is about 20503.7413415211. The cubic root of 420403409 is about 749.1269301338.

The spelling of 420403409 in words is "four hundred twenty million, four hundred three thousand, four hundred nine".