231221767493 has 2 divisors, whose sum is σ = 231221767494. Its totient is φ = 231221767492.

The previous prime is 231221767459. The next prime is 231221767603. The reversal of 231221767493 is 394767122132.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156295296964 + 74926470529 = 395342^2 + 273727^2 .

It is a cyclic number.

It is not a de Polignac number, because 231221767493 - 2²⁰ = 231220718917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231221767093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610883746 + 115610883747.

It is an arithmetic number, because the mean of its divisors is an integer number (115610883747).

Almost surely, 2^231221767493 is an apocalyptic number.

It is an amenable number.

231221767493 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221767493 is an equidigital number, since it uses as much as digits as its factorization.

231221767493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 47.

The spelling of 231221767493 in words is "two hundred thirty-one billion, two hundred twenty-one million, seven hundred sixty-seven thousand, four hundred ninety-three".