231021099989 has 2 divisors, whose sum is σ = 231021099990. Its totient is φ = 231021099988.

The previous prime is 231021099979. The next prime is 231021100027. The reversal of 231021099989 is 989990120132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151930787089 + 79090312900 = 389783^2 + 281230^2 .

It is a cyclic number.

It is not a de Polignac number, because 231021099989 - 2⁸ = 231021099733 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 231021099989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231021099929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115510549994 + 115510549995.

It is an arithmetic number, because the mean of its divisors is an integer number (115510549995).

Almost surely, 2^231021099989 is an apocalyptic number.

It is an amenable number.

231021099989 is a deficient number, since it is larger than the sum of its proper divisors (1).

231021099989 is an equidigital number, since it uses as much as digits as its factorization.

231021099989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 53.

The spelling of 231021099989 in words is "two hundred thirty-one billion, twenty-one million, ninety-nine thousand, nine hundred eighty-nine".