66390823 has 2 divisors, whose sum is σ = 66390824. Its totient is φ = 66390822.

The previous prime is 66390817. The next prime is 66390827. The reversal of 66390823 is 32809366.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66390823 - 2⁵ = 66390791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66390827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33195411 + 33195412.

It is an arithmetic number, because the mean of its divisors is an integer number (33195412).

Almost surely, 2^66390823 is an apocalyptic number.

66390823 is a deficient number, since it is larger than the sum of its proper divisors (1).

66390823 is an equidigital number, since it uses as much as digits as its factorization.

66390823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 66390823 is about 8148.0563940120. The cubic root of 66390823 is about 404.9201143052.

The spelling of 66390823 in words is "sixty-six million, three hundred ninety thousand, eight hundred twenty-three".