66279172649 has 2 divisors, whose sum is σ = 66279172650. Its totient is φ = 66279172648.

The previous prime is 66279172621. The next prime is 66279172681. The reversal of 66279172649 is 94627197266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46443267049 + 19835905600 = 215507^2 + 140840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66279172649 is a prime.

It is not a weakly prime, because it can be changed into another prime (66279172249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33139586324 + 33139586325.

It is an arithmetic number, because the mean of its divisors is an integer number (33139586325).

Almost surely, 2^66279172649 is an apocalyptic number.

It is an amenable number.

66279172649 is a deficient number, since it is larger than the sum of its proper divisors (1).

66279172649 is an equidigital number, since it uses as much as digits as its factorization.

66279172649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13716864, while the sum is 59.

The spelling of 66279172649 in words is "sixty-six billion, two hundred seventy-nine million, one hundred seventy-two thousand, six hundred forty-nine".