421521 has 16 divisors (see below), whose sum is σ = 604800. Its totient is φ = 260480.

The previous prime is 421517. The next prime is 421559. The reversal of 421521 is 125124.

It is a cyclic number.

It is not a de Polignac number, because 421521 - 2² = 421517 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 421521.

It is not an unprimeable number, because it can be changed into a prime (421501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2755 + ... + 2903.

It is an arithmetic number, because the mean of its divisors is an integer number (37800).

2⁴²¹⁵²¹ is an apocalyptic number.

421521 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

421521 is a deficient number, since it is larger than the sum of its proper divisors (183279).

421521 is a wasteful number, since it uses less digits than its factorization.

421521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216.

The product of its digits is 80, while the sum is 15.

The square root of 421521 is about 649.2464863209. The cubic root of 421521 is about 74.9790163519.

Adding to 421521 its reverse (125124), we get a palindrome (546645).

The spelling of 421521 in words is "four hundred twenty-one thousand, five hundred twenty-one".