66419657 has 6 divisors (see below), whose sum is σ = 68789838. Its totient is φ = 64128512.

The previous prime is 66419651. The next prime is 66419669. The reversal of 66419657 is 75691466.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 33884041 + 32535616 = 5821^2 + 5704^2 .

It is not a de Polignac number, because 66419657 - 2⁶ = 66419593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66419651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38648 + ... + 40329.

It is an arithmetic number, because the mean of its divisors is an integer number (11464973).

Almost surely, 2^66419657 is an apocalyptic number.

It is an amenable number.

66419657 is a deficient number, since it is larger than the sum of its proper divisors (2370181).

66419657 is an equidigital number, since it uses as much as digits as its factorization.

66419657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79035 (or 79006 counting only the distinct ones).

The product of its digits is 272160, while the sum is 44.

The square root of 66419657 is about 8149.8255809557. The cubic root of 66419657 is about 404.9787257026.

It can be divided in two parts, 66419 and 657, that added together give a palindrome (67076).

The spelling of 66419657 in words is "sixty-six million, four hundred nineteen thousand, six hundred fifty-seven".