12783744175621 has 2 divisors, whose sum is σ = 12783744175622. Its totient is φ = 12783744175620.

The previous prime is 12783744175603. The next prime is 12783744175651. The reversal of 12783744175621 is 12657144738721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9702982031521 + 3080762144100 = 3114961^2 + 1755210^2 .

It is a cyclic number.

It is not a de Polignac number, because 12783744175621 - 2²³ = 12783735787013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12783744175651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6391872087810 + 6391872087811.

It is an arithmetic number, because the mean of its divisors is an integer number (6391872087811).

Almost surely, 2^{12783744175621} is an apocalyptic number.

It is an amenable number.

12783744175621 is a deficient number, since it is larger than the sum of its proper divisors (1).

12783744175621 is an equidigital number, since it uses as much as digits as its factorization.

12783744175621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15805440, while the sum is 58.

The spelling of 12783744175621 in words is "twelve trillion, seven hundred eighty-three billion, seven hundred forty-four million, one hundred seventy-five thousand, six hundred twenty-one".