421205231 has 4 divisors (see below), whose sum is σ = 422704464. Its totient is φ = 419706000.

The previous prime is 421205221. The next prime is 421205237. The reversal of 421205231 is 132502124.

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 421205231 - 2¹⁸ = 420943087 is a prime.

It is a super-2 number, since 2×421205231² = 354827693243526722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421205237) 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, 749195 + ... + 749756.

It is an arithmetic number, because the mean of its divisors is an integer number (105676116).

Almost surely, 2^421205231 is an apocalyptic number.

421205231 is a deficient number, since it is larger than the sum of its proper divisors (1499233).

421205231 is a wasteful number, since it uses less digits than its factorization.

421205231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1499232.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 421205231 is about 20523.2850927916. The cubic root of 421205231 is about 749.6028896268.

Adding to 421205231 its reverse (132502124), we get a palindrome (553707355).

The spelling of 421205231 in words is "four hundred twenty-one million, two hundred five thousand, two hundred thirty-one".