66622590649 has 2 divisors, whose sum is σ = 66622590650. Its totient is φ = 66622590648.

The previous prime is 66622590647. The next prime is 66622590731. The reversal of 66622590649 is 94609522666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61931299600 + 4691291049 = 248860^2 + 68493^2 .

It is a cyclic number.

It is not a de Polignac number, because 66622590649 - 2¹ = 66622590647 is a prime.

Together with 66622590647, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66622590649.

It is not a weakly prime, because it can be changed into another prime (66622590647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33311295324 + 33311295325.

It is an arithmetic number, because the mean of its divisors is an integer number (33311295325).

Almost surely, 2^66622590649 is an apocalyptic number.

It is an amenable number.

66622590649 is a deficient number, since it is larger than the sum of its proper divisors (1).

66622590649 is an equidigital number, since it uses as much as digits as its factorization.

66622590649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8398080, while the sum is 55.

The spelling of 66622590649 in words is "sixty-six billion, six hundred twenty-two million, five hundred ninety thousand, six hundred forty-nine".