231520421 has 8 divisors (see below), whose sum is σ = 256125888. Its totient is φ = 207508000.

The previous prime is 231520411. The next prime is 231520441. The reversal of 231520421 is 124025132.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 231520421 - 2¹⁸ = 231258277 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 231520393 and 231520402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231520411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 147440 + ... + 149001.

It is an arithmetic number, because the mean of its divisors is an integer number (32015736).

Almost surely, 2^231520421 is an apocalyptic number.

It is an amenable number.

231520421 is a deficient number, since it is larger than the sum of its proper divisors (24605467).

231520421 is a wasteful number, since it uses less digits than its factorization.

231520421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296523.

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

The square root of 231520421 is about 15215.7951156027. The cubic root of 231520421 is about 614.0396769021.

Adding to 231520421 its reverse (124025132), we get a palindrome (355545553).

The spelling of 231520421 in words is "two hundred thirty-one million, five hundred twenty thousand, four hundred twenty-one".