20673399917 has 2 divisors, whose sum is σ = 20673399918. Its totient is φ = 20673399916.

The previous prime is 20673399847. The next prime is 20673399941. The reversal of 20673399917 is 71999337602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13847170276 + 6826229641 = 117674^2 + 82621^2 .

It is a cyclic number.

It is not a de Polignac number, because 20673399917 - 2¹⁸ = 20673137773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20673399317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10336699958 + 10336699959.

It is an arithmetic number, because the mean of its divisors is an integer number (10336699959).

Almost surely, 2^20673399917 is an apocalyptic number.

It is an amenable number.

20673399917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20673399917 is an equidigital number, since it uses as much as digits as its factorization.

20673399917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3857868, while the sum is 56.

The spelling of 20673399917 in words is "twenty billion, six hundred seventy-three million, three hundred ninety-nine thousand, nine hundred seventeen".