421420217 has 2 divisors, whose sum is σ = 421420218. Its totient is φ = 421420216.

The previous prime is 421420201. The next prime is 421420243. The reversal of 421420217 is 712024124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 288456256 + 132963961 = 16984^2 + 11531^2 .

It is a cyclic number.

It is not a de Polignac number, because 421420217 - 2⁴ = 421420201 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 421420192 and 421420201.

It is not a weakly prime, because it can be changed into another prime (421420267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210710108 + 210710109.

It is an arithmetic number, because the mean of its divisors is an integer number (210710109).

Almost surely, 2^421420217 is an apocalyptic number.

It is an amenable number.

421420217 is a deficient number, since it is larger than the sum of its proper divisors (1).

421420217 is an equidigital number, since it uses as much as digits as its factorization.

421420217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 421420217 is about 20528.5220364253. The cubic root of 421420217 is about 749.7304020638.

The spelling of 421420217 in words is "four hundred twenty-one million, four hundred twenty thousand, two hundred seventeen".