231811973 has 2 divisors, whose sum is σ = 231811974. Its totient is φ = 231811972.

The previous prime is 231811961. The next prime is 231811997. The reversal of 231811973 is 379118132.

It is a happy number.

231811973 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220908769 + 10903204 = 14863^2 + 3302^2 .

It is a cyclic number.

It is not a de Polignac number, because 231811973 - 2²⁰ = 230763397 is a prime.

It is a super-5 number, since 5×231811973⁵ (a number of 43 digits) contains 55555 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231810973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115905986 + 115905987.

It is an arithmetic number, because the mean of its divisors is an integer number (115905987).

Almost surely, 2^231811973 is an apocalyptic number.

It is an amenable number.

231811973 is a deficient number, since it is larger than the sum of its proper divisors (1).

231811973 is an equidigital number, since it uses as much as digits as its factorization.

231811973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 35.

The square root of 231811973 is about 15225.3726719578. The cubic root of 231811973 is about 614.2973206981.

The spelling of 231811973 in words is "two hundred thirty-one million, eight hundred eleven thousand, nine hundred seventy-three".