21738934565507 has 2 divisors, whose sum is σ = 21738934565508. Its totient is φ = 21738934565506.

The previous prime is 21738934565437. The next prime is 21738934565521. The reversal of 21738934565507 is 70556543983712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21738934565507 - 2¹² = 21738934561411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21738934565527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10869467282753 + 10869467282754.

It is an arithmetic number, because the mean of its divisors is an integer number (10869467282754).

It is a 1-persistent number, because it is pandigital, but 2⋅21738934565507 = 43477869131014 is not.

Almost surely, 2^{21738934565507} is an apocalyptic number.

21738934565507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21738934565507 is an equidigital number, since it uses as much as digits as its factorization.

21738934565507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512000, while the sum is 65.

The spelling of 21738934565507 in words is "twenty-one trillion, seven hundred thirty-eight billion, nine hundred thirty-four million, five hundred sixty-five thousand, five hundred seven".