420647217 has 4 divisors (see below), whose sum is σ = 560862960. Its totient is φ = 280431476.

The previous prime is 420647189. The next prime is 420647219. The reversal of 420647217 is 712746024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 420647217 - 2¹⁹ = 420122929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (420647219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70107867 + ... + 70107872.

It is an arithmetic number, because the mean of its divisors is an integer number (140215740).

Almost surely, 2^420647217 is an apocalyptic number.

It is an amenable number.

420647217 is a deficient number, since it is larger than the sum of its proper divisors (140215743).

420647217 is a wasteful number, since it uses less digits than its factorization.

420647217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140215742.

The product of its (nonzero) digits is 18816, while the sum is 33.

The square root of 420647217 is about 20509.6859312862. The cubic root of 420647217 is about 749.2717179248.

The spelling of 420647217 in words is "four hundred twenty million, six hundred forty-seven thousand, two hundred seventeen".