16638656579 has 2 divisors, whose sum is σ = 16638656580. Its totient is φ = 16638656578.

The previous prime is 16638656569. The next prime is 16638656599. The reversal of 16638656579 is 97565683661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16638656579 - 2¹² = 16638652483 is a prime.

It is not a weakly prime, because it can be changed into another prime (16638656539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8319328289 + 8319328290.

It is an arithmetic number, because the mean of its divisors is an integer number (8319328290).

Almost surely, 2^16638656579 is an apocalyptic number.

16638656579 is a deficient number, since it is larger than the sum of its proper divisors (1).

16638656579 is an equidigital number, since it uses as much as digits as its factorization.

16638656579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48988800, while the sum is 62.

The spelling of 16638656579 in words is "sixteen billion, six hundred thirty-eight million, six hundred fifty-six thousand, five hundred seventy-nine".