231742521 has 12 divisors (see below), whose sum is σ = 354429972. Its totient is φ = 145406976.

The previous prime is 231742513. The next prime is 231742541. The reversal of 231742521 is 125247132.

231742521 is a `hidden beast` number, since 231 + 7 + 425 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 97298496 + 134444025 = 9864^2 + 11595^2 .

It is not a de Polignac number, because 231742521 - 2³ = 231742513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231742541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 757176 + ... + 757481.

It is an arithmetic number, because the mean of its divisors is an integer number (29535831).

Almost surely, 2^231742521 is an apocalyptic number.

It is an amenable number.

231742521 is a deficient number, since it is larger than the sum of its proper divisors (122687451).

231742521 is a wasteful number, since it uses less digits than its factorization.

231742521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1514680 (or 1514677 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 231742521 is about 15223.0917030674. The cubic root of 231742521 is about 614.2359657438.

Adding to 231742521 its reverse (125247132), we get a palindrome (356989653).

The spelling of 231742521 in words is "two hundred thirty-one million, seven hundred forty-two thousand, five hundred twenty-one".