421531 has 4 divisors (see below), whose sum is σ = 459864. Its totient is φ = 383200.

The previous prime is 421517. The next prime is 421559. The reversal of 421531 is 135124.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 421531 - 2⁹ = 421019 is a prime.

It is a super-2 number, since 2×421531² = 355376767922, which contains 22 as substring.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 19150 + ... + 19171.

It is an arithmetic number, because the mean of its divisors is an integer number (114966).

2⁴²¹⁵³¹ is an apocalyptic number.

421531 is a deficient number, since it is larger than the sum of its proper divisors (38333).

421531 is a wasteful number, since it uses less digits than its factorization.

421531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38332.

The product of its digits is 120, while the sum is 16.

The square root of 421531 is about 649.2541875106. The cubic root of 421531 is about 74.9796092716.

Adding to 421531 its reverse (135124), we get a palindrome (556655).

The spelling of 421531 in words is "four hundred twenty-one thousand, five hundred thirty-one".