19966534573 has 2 divisors, whose sum is σ = 19966534574. Its totient is φ = 19966534572.

The previous prime is 19966534507. The next prime is 19966534583. The reversal of 19966534573 is 37543566991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15796216489 + 4170318084 = 125683^2 + 64578^2 .

It is a cyclic number.

It is not a de Polignac number, because 19966534573 - 2¹³ = 19966526381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19966534583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9983267286 + 9983267287.

It is an arithmetic number, because the mean of its divisors is an integer number (9983267287).

Almost surely, 2^19966534573 is an apocalyptic number.

It is an amenable number.

19966534573 is a deficient number, since it is larger than the sum of its proper divisors (1).

19966534573 is an equidigital number, since it uses as much as digits as its factorization.

19966534573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18370800, while the sum is 58.

The spelling of 19966534573 in words is "nineteen billion, nine hundred sixty-six million, five hundred thirty-four thousand, five hundred seventy-three".