13540021609 has 2 divisors, whose sum is σ = 13540021610. Its totient is φ = 13540021608.

The previous prime is 13540021591. The next prime is 13540021631. The reversal of 13540021609 is 90612004531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8986471209 + 4553550400 = 94797^2 + 67480^2 .

It is a cyclic number.

It is not a de Polignac number, because 13540021609 - 2¹¹ = 13540019561 is a prime.

It is not a weakly prime, because it can be changed into another prime (13540021309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6770010804 + 6770010805.

It is an arithmetic number, because the mean of its divisors is an integer number (6770010805).

Almost surely, 2^13540021609 is an apocalyptic number.

It is an amenable number.

13540021609 is a deficient number, since it is larger than the sum of its proper divisors (1).

13540021609 is an equidigital number, since it uses as much as digits as its factorization.

13540021609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 13540021609 in words is "thirteen billion, five hundred forty million, twenty-one thousand, six hundred nine".