420564 has 24 divisors (see below), whose sum is σ = 993888. Its totient is φ = 138400.

The previous prime is 420557. The next prime is 420569. The reversal of 420564 is 465024.

It is a happy number.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 420564.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420569) by changing a digit.

420564 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1039 + ... + 1385.

It is an arithmetic number, because the mean of its divisors is an integer number (41412).

2⁴²⁰⁵⁶⁴ is an apocalyptic number.

420564 is the 347-th nonagonal number.

It is an amenable number.

420564 is an abundant number, since it is smaller than the sum of its proper divisors (573324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

420564 is a wasteful number, since it uses less digits than its factorization.

420564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 420564 is about 648.5090593045. The cubic root of 420564 is about 74.9222304977.

Adding to 420564 its reverse (465024), we get a palindrome (885588).

The spelling of 420564 in words is "four hundred twenty thousand, five hundred sixty-four".