66823837 has 2 divisors, whose sum is σ = 66823838. Its totient is φ = 66823836.

The previous prime is 66823819. The next prime is 66823871. The reversal of 66823837 is 73832866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65464281 + 1359556 = 8091^2 + 1166^2 .

It is a cyclic number.

It is not a de Polignac number, because 66823837 - 2²³ = 58435229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66823793 and 66823802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66823877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33411918 + 33411919.

It is an arithmetic number, because the mean of its divisors is an integer number (33411919).

Almost surely, 2^66823837 is an apocalyptic number.

It is an amenable number.

66823837 is a deficient number, since it is larger than the sum of its proper divisors (1).

66823837 is an equidigital number, since it uses as much as digits as its factorization.

66823837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 43.

The square root of 66823837 is about 8174.5848212616. The cubic root of 66823837 is about 405.7985301946.

The spelling of 66823837 in words is "sixty-six million, eight hundred twenty-three thousand, eight hundred thirty-seven".