13578565421 has 2 divisors, whose sum is σ = 13578565422. Its totient is φ = 13578565420.

The previous prime is 13578565381. The next prime is 13578565433. The reversal of 13578565421 is 12456587531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12862735396 + 715830025 = 113414^2 + 26755^2 .

It is a cyclic number.

It is not a de Polignac number, because 13578565421 - 2²⁶ = 13511456557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13578561421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6789282710 + 6789282711.

It is an arithmetic number, because the mean of its divisors is an integer number (6789282711).

Almost surely, 2^13578565421 is an apocalyptic number.

It is an amenable number.

13578565421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13578565421 is an equidigital number, since it uses as much as digits as its factorization.

13578565421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008000, while the sum is 47.

The spelling of 13578565421 in words is "thirteen billion, five hundred seventy-eight million, five hundred sixty-five thousand, four hundred twenty-one".