16643939503 has 2 divisors, whose sum is σ = 16643939504. Its totient is φ = 16643939502.

The previous prime is 16643939399. The next prime is 16643939551. The reversal of 16643939503 is 30593934661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16643939503 - 2³³ = 8054004911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16643939563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8321969751 + 8321969752.

It is an arithmetic number, because the mean of its divisors is an integer number (8321969752).

Almost surely, 2^16643939503 is an apocalyptic number.

16643939503 is a deficient number, since it is larger than the sum of its proper divisors (1).

16643939503 is an equidigital number, since it uses as much as digits as its factorization.

16643939503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1574640, while the sum is 49.

The spelling of 16643939503 in words is "sixteen billion, six hundred forty-three million, nine hundred thirty-nine thousand, five hundred three".