66389501 has 2 divisors, whose sum is σ = 66389502. Its totient is φ = 66389500.

The previous prime is 66389447. The next prime is 66389503. The reversal of 66389501 is 10598366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43099225 + 23290276 = 6565^2 + 4826^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66389501 is a prime.

Together with 66389503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66389503) 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, 33194750 + 33194751.

It is an arithmetic number, because the mean of its divisors is an integer number (33194751).

Almost surely, 2^66389501 is an apocalyptic number.

It is an amenable number.

66389501 is a deficient number, since it is larger than the sum of its proper divisors (1).

66389501 is an equidigital number, since it uses as much as digits as its factorization.

66389501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 66389501 is about 8147.9752699674. The cubic root of 66389501 is about 404.9174266448.

The spelling of 66389501 in words is "sixty-six million, three hundred eighty-nine thousand, five hundred one".