231543397109 has 2 divisors, whose sum is σ = 231543397110. Its totient is φ = 231543397108.

The previous prime is 231543397081. The next prime is 231543397123. The reversal of 231543397109 is 901793345132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 230837007025 + 706390084 = 480455^2 + 26578^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231543397109 is a prime.

It is a super-2 number, since 2×231543397109² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231543397199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115771698554 + 115771698555.

It is an arithmetic number, because the mean of its divisors is an integer number (115771698555).

Almost surely, 2^231543397109 is an apocalyptic number.

It is an amenable number.

231543397109 is a deficient number, since it is larger than the sum of its proper divisors (1).

231543397109 is an equidigital number, since it uses as much as digits as its factorization.

231543397109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 612360, while the sum is 47.

The spelling of 231543397109 in words is "two hundred thirty-one billion, five hundred forty-three million, three hundred ninety-seven thousand, one hundred nine".