66354199979 has 2 divisors, whose sum is σ = 66354199980. Its totient is φ = 66354199978.

The previous prime is 66354199973. The next prime is 66354200111. The reversal of 66354199979 is 97999145366.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66354199979 is a prime.

It is not a weakly prime, because it can be changed into another prime (66354199973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33177099989 + 33177099990.

It is an arithmetic number, because the mean of its divisors is an integer number (33177099990).

Almost surely, 2^66354199979 is an apocalyptic number.

66354199979 is a deficient number, since it is larger than the sum of its proper divisors (1).

66354199979 is an equidigital number, since it uses as much as digits as its factorization.

66354199979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 99202320, while the sum is 68.

The spelling of 66354199979 in words is "sixty-six billion, three hundred fifty-four million, one hundred ninety-nine thousand, nine hundred seventy-nine".