243212421 has 16 divisors (see below), whose sum is σ = 348067584. Its totient is φ = 150511104.

The previous prime is 243212413. The next prime is 243212441. The reversal of 243212421 is 124212342.

243212421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 243212421 - 2³ = 243212413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243212441) 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, 28941 + ... + 36386.

It is an arithmetic number, because the mean of its divisors is an integer number (21754224).

Almost surely, 2^243212421 is an apocalyptic number.

It is an amenable number.

243212421 is a deficient number, since it is larger than the sum of its proper divisors (104855163).

243212421 is a wasteful number, since it uses less digits than its factorization.

243212421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65420.

The product of its digits is 768, while the sum is 21.

The square root of 243212421 is about 15595.2691865194. The cubic root of 243212421 is about 624.2069266678.

Adding to 243212421 its reverse (124212342), we get a palindrome (367424763).

The spelling of 243212421 in words is "two hundred forty-three million, two hundred twelve thousand, four hundred twenty-one".