66579649 has 2 divisors, whose sum is σ = 66579650. Its totient is φ = 66579648.

The previous prime is 66579637. The next prime is 66579677. The reversal of 66579649 is 94697566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59985025 + 6594624 = 7745^2 + 2568^2 .

It is a cyclic number.

It is not a de Polignac number, because 66579649 - 2⁷ = 66579521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66579596 and 66579605.

It is not a weakly prime, because it can be changed into another prime (66570649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33289824 + 33289825.

It is an arithmetic number, because the mean of its divisors is an integer number (33289825).

Almost surely, 2^66579649 is an apocalyptic number.

It is an amenable number.

66579649 is a deficient number, since it is larger than the sum of its proper divisors (1).

66579649 is an equidigital number, since it uses as much as digits as its factorization.

66579649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2449440, while the sum is 52.

The square root of 66579649 is about 8159.6353472444. The cubic root of 66579649 is about 405.3036365491.

The spelling of 66579649 in words is "sixty-six million, five hundred seventy-nine thousand, six hundred forty-nine".