66013732649 has 2 divisors, whose sum is σ = 66013732650. Its totient is φ = 66013732648.

The previous prime is 66013732633. The next prime is 66013732709. The reversal of 66013732649 is 94623731066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51719856400 + 14293876249 = 227420^2 + 119557^2 .

It is a cyclic number.

It is not a de Polignac number, because 66013732649 - 2⁴ = 66013732633 is a prime.

It is not a weakly prime, because it can be changed into another prime (66013732549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33006866324 + 33006866325.

It is an arithmetic number, because the mean of its divisors is an integer number (33006866325).

Almost surely, 2^66013732649 is an apocalyptic number.

It is an amenable number.

66013732649 is a deficient number, since it is larger than the sum of its proper divisors (1).

66013732649 is an equidigital number, since it uses as much as digits as its factorization.

66013732649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 47.

The spelling of 66013732649 in words is "sixty-six billion, thirteen million, seven hundred thirty-two thousand, six hundred forty-nine".