66789601 has 2 divisors, whose sum is σ = 66789602. Its totient is φ = 66789600.

The previous prime is 66789599. The next prime is 66789607. The reversal of 66789601 is 10698766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49350625 + 17438976 = 7025^2 + 4176^2 .

It is a cyclic number.

It is not a de Polignac number, because 66789601 - 2¹ = 66789599 is a prime.

Together with 66789599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66789607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33394800 + 33394801.

It is an arithmetic number, because the mean of its divisors is an integer number (33394801).

Almost surely, 2^66789601 is an apocalyptic number.

It is an amenable number.

66789601 is a deficient number, since it is larger than the sum of its proper divisors (1).

66789601 is an equidigital number, since it uses as much as digits as its factorization.

66789601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 66789601 is about 8172.4905016770. The cubic root of 66789601 is about 405.7292171451.

The spelling of 66789601 in words is "sixty-six million, seven hundred eighty-nine thousand, six hundred one".