71823765036421 has 2 divisors, whose sum is σ = 71823765036422. Its totient is φ = 71823765036420.

The previous prime is 71823765036337. The next prime is 71823765036487. The reversal of 71823765036421 is 12463056732817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41517583975396 + 30306181061025 = 6443414^2 + 5505105^2 .

It is a cyclic number.

It is not a de Polignac number, because 71823765036421 - 2⁹ = 71823765035909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71823765037421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35911882518210 + 35911882518211.

It is an arithmetic number, because the mean of its divisors is an integer number (35911882518211).

Almost surely, 2^{71823765036421} is an apocalyptic number.

It is an amenable number.

71823765036421 is a deficient number, since it is larger than the sum of its proper divisors (1).

71823765036421 is an equidigital number, since it uses as much as digits as its factorization.

71823765036421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10160640, while the sum is 55.

The spelling of 71823765036421 in words is "seventy-one trillion, eight hundred twenty-three billion, seven hundred sixty-five million, thirty-six thousand, four hundred twenty-one".