66420593 has 4 divisors (see below), whose sum is σ = 67261440. Its totient is φ = 65579748.

The previous prime is 66420559. The next prime is 66420671. The reversal of 66420593 is 39502466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66420593 - 2¹⁶ = 66355057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66420503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 420305 + ... + 420462.

It is an arithmetic number, because the mean of its divisors is an integer number (16815360).

Almost surely, 2^66420593 is an apocalyptic number.

It is an amenable number.

66420593 is a deficient number, since it is larger than the sum of its proper divisors (840847).

66420593 is an equidigital number, since it uses as much as digits as its factorization.

66420593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840846.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 66420593 is about 8149.8830052952. The cubic root of 66420593 is about 404.9806280426.

The spelling of 66420593 in words is "sixty-six million, four hundred twenty thousand, five hundred ninety-three".