66611837 has 2 divisors, whose sum is σ = 66611838. Its totient is φ = 66611836.

The previous prime is 66611833. The next prime is 66611849. The reversal of 66611837 is 73811666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65108761 + 1503076 = 8069^2 + 1226^2 .

It is a cyclic number.

It is not a de Polignac number, because 66611837 - 2² = 66611833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66611837.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66611833) 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, 33305918 + 33305919.

It is an arithmetic number, because the mean of its divisors is an integer number (33305919).

Almost surely, 2^66611837 is an apocalyptic number.

It is an amenable number.

66611837 is a deficient number, since it is larger than the sum of its proper divisors (1).

66611837 is an equidigital number, since it uses as much as digits as its factorization.

66611837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 66611837 is about 8161.6075009768. The cubic root of 66611837 is about 405.3689408468.

The spelling of 66611837 in words is "sixty-six million, six hundred eleven thousand, eight hundred thirty-seven".