421564 has 36 divisors (see below), whose sum is σ = 886312. Its totient is φ = 174240.

The previous prime is 421559. The next prime is 421607. The reversal of 421564 is 465124.

421564 = T₇₇ + T₇₈ + ... + T₁₄₃.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

421564 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 11 ways as a sum of consecutive naturals, for example, 6259 + ... + 6325.

2⁴²¹⁵⁶⁴ is an apocalyptic number.

421564 is a gapful number since it is divisible by the number (44) formed by its first and last digit.

It is an amenable number.

421564 is an abundant number, since it is smaller than the sum of its proper divisors (464748).

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

421564 is a wasteful number, since it uses less digits than its factorization.

421564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 93 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 421564 is about 649.2796007884. The cubic root of 421564 is about 74.9815658398.

Adding to 421564 its reverse (465124), we get a palindrome (886688).

The spelling of 421564 in words is "four hundred twenty-one thousand, five hundred sixty-four".