231611857 has 4 divisors (see below), whose sum is σ = 231833700. Its totient is φ = 231390016.

The previous prime is 231611851. The next prime is 231611923. The reversal of 231611857 is 758116132.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 215619856 + 15992001 = 14684^2 + 3999^2 .

It is a cyclic number.

It is not a de Polignac number, because 231611857 - 2¹¹ = 231609809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231611851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109348 + ... + 111445.

It is an arithmetic number, because the mean of its divisors is an integer number (57958425).

Almost surely, 2^231611857 is an apocalyptic number.

It is an amenable number.

231611857 is a deficient number, since it is larger than the sum of its proper divisors (221843).

231611857 is a wasteful number, since it uses less digits than its factorization.

231611857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221842.

The product of its digits is 10080, while the sum is 34.

The square root of 231611857 is about 15218.7994598786. The cubic root of 231611857 is about 614.1205019426.

Adding to 231611857 its reverse (758116132), we get a palindrome (989727989).

The spelling of 231611857 in words is "two hundred thirty-one million, six hundred eleven thousand, eight hundred fifty-seven".