231131816 has 8 divisors (see below), whose sum is σ = 433372170. Its totient is φ = 115565904.

The previous prime is 231131809. The next prime is 231131833. The reversal of 231131816 is 618131132.

231131816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 207648100 + 23483716 = 14410^2 + 4846^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14445731 + ... + 14445746.

Almost surely, 2^231131816 is an apocalyptic number.

It is an amenable number.

231131816 is a deficient number, since it is larger than the sum of its proper divisors (202240354).

231131816 is a wasteful number, since it uses less digits than its factorization.

231131816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28891483 (or 28891479 counting only the distinct ones).

The product of its digits is 864, while the sum is 26.

The square root of 231131816 is about 15203.0199631521. The cubic root of 231131816 is about 613.6959310980.

Adding to 231131816 its reverse (618131132), we get a palindrome (849262948).

The spelling of 231131816 in words is "two hundred thirty-one million, one hundred thirty-one thousand, eight hundred sixteen".