231557 has 8 divisors (see below), whose sum is σ = 250776. Its totient is φ = 212992.

The previous prime is 231551. The next prime is 231559. The reversal of 231557 is 755132.

It can be written as a sum of positive squares in 4 ways, for example, as 160801 + 70756 = 401^2 + 266^2 .

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

It is a 7-Lehmer number, since φ(231557) divides (231557-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 231557 - 2⁶ = 231493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 773 + ... + 1029.

It is an arithmetic number, because the mean of its divisors is an integer number (31347).

2²³¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

231557 is a deficient number, since it is larger than the sum of its proper divisors (19219).

231557 is a wasteful number, since it uses less digits than its factorization.

231557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327.

The product of its digits is 1050, while the sum is 23.

The square root of 231557 is about 481.2036990714. The cubic root of 231557 is about 61.4072013538.

Adding to 231557 its reverse (755132), we get a palindrome (986689).

The spelling of 231557 in words is "two hundred thirty-one thousand, five hundred fifty-seven".