16643157779 has 2 divisors, whose sum is σ = 16643157780. Its totient is φ = 16643157778.

The previous prime is 16643157761. The next prime is 16643157793. The reversal of 16643157779 is 97775134661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16643157779 - 2¹⁶ = 16643092243 is a prime.

It is not a weakly prime, because it can be changed into another prime (16643157079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8321578889 + 8321578890.

It is an arithmetic number, because the mean of its divisors is an integer number (8321578890).

Almost surely, 2^16643157779 is an apocalyptic number.

16643157779 is a deficient number, since it is larger than the sum of its proper divisors (1).

16643157779 is an equidigital number, since it uses as much as digits as its factorization.

16643157779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6667920, while the sum is 56.

The spelling of 16643157779 in words is "sixteen billion, six hundred forty-three million, one hundred fifty-seven thousand, seven hundred seventy-nine".