231240021 has 8 divisors (see below), whose sum is σ = 310674144. Its totient is φ = 152982960.

The previous prime is 231240019. The next prime is 231240029. The reversal of 231240021 is 120042132.

231240021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 231240021 - 2¹ = 231240019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231240029) 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, 293806 + ... + 294591.

It is an arithmetic number, because the mean of its divisors is an integer number (38834268).

Almost surely, 2^231240021 is an apocalyptic number.

It is an amenable number.

231240021 is a deficient number, since it is larger than the sum of its proper divisors (79434123).

231240021 is a wasteful number, since it uses less digits than its factorization.

231240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588531.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 231240021 is about 15206.5782147069. The cubic root of 231240021 is about 613.7916839740.

Adding to 231240021 its reverse (120042132), we get a palindrome (351282153).

The spelling of 231240021 in words is "two hundred thirty-one million, two hundred forty thousand, twenty-one".