420816809 has 8 divisors (see below), whose sum is σ = 501843840. Its totient is φ = 345017376.

The previous prime is 420816779. The next prime is 420816817. The reversal of 420816809 is 908618024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420816809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (420816509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1306724 + ... + 1307045.

It is an arithmetic number, because the mean of its divisors is an integer number (62730480).

Almost surely, 2^420816809 is an apocalyptic number.

It is an amenable number.

420816809 is a deficient number, since it is larger than the sum of its proper divisors (81027031).

420816809 is a wasteful number, since it uses less digits than its factorization.

420816809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2613799.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 420816809 is about 20513.8199514376. The cubic root of 420816809 is about 749.3723988207.

The spelling of 420816809 in words is "four hundred twenty million, eight hundred sixteen thousand, eight hundred nine".