66237813 has 12 divisors (see below), whose sum is σ = 95767308. Its totient is φ = 44116800.

The previous prime is 66237799. The next prime is 66237833. The reversal of 66237813 is 31873266.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2125764 + 64112049 = 1458^2 + 8007^2 .

It is not a de Polignac number, because 66237813 - 2⁶ = 66237749 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66237833) 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 11 ways as a sum of consecutive naturals, for example, 8881 + ... + 14537.

It is an arithmetic number, because the mean of its divisors is an integer number (7980609).

Almost surely, 2^66237813 is an apocalyptic number.

It is an amenable number.

66237813 is a deficient number, since it is larger than the sum of its proper divisors (29529495).

66237813 is a wasteful number, since it uses less digits than its factorization.

66237813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6964 (or 6961 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 66237813 is about 8138.6616221588. The cubic root of 66237813 is about 404.6088037860.

The spelling of 66237813 in words is "sixty-six million, two hundred thirty-seven thousand, eight hundred thirteen".