66985641 has 6 divisors (see below), whose sum is σ = 96757050. Its totient is φ = 44657088.

The previous prime is 66985631. The next prime is 66985673. The reversal of 66985641 is 14658966.

It can be written as a sum of positive squares in only one way, i.e., 58982400 + 8003241 = 7680^2 + 2829^2 .

It is not a de Polignac number, because 66985641 - 2⁹ = 66985129 is a prime.

It is a super-2 number, since 2×66985641² = 8974152200361762, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66985631) 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 in 5 ways as a sum of consecutive naturals, for example, 3721416 + ... + 3721433.

It is an arithmetic number, because the mean of its divisors is an integer number (16126175).

Almost surely, 2^66985641 is an apocalyptic number.

It is an amenable number.

66985641 is a deficient number, since it is larger than the sum of its proper divisors (29771409).

66985641 is a wasteful number, since it uses less digits than its factorization.

66985641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7442855 (or 7442852 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 66985641 is about 8184.4756093472. The cubic root of 66985641 is about 406.1257931610.

The spelling of 66985641 in words is "sixty-six million, nine hundred eighty-five thousand, six hundred forty-one".