66427321 has 4 divisors (see below), whose sum is σ = 68222692. Its totient is φ = 64631952.

The previous prime is 66427301. The next prime is 66427337. The reversal of 66427321 is 12372466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12372466 = 2 ⋅6186233.

It can be written as a sum of positive squares in 2 ways, for example, as 30858025 + 35569296 = 5555^2 + 5964^2 .

It is a cyclic number.

It is not a de Polignac number, because 66427321 - 2¹⁵ = 66394553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66427301) 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 3 ways as a sum of consecutive naturals, for example, 897630 + ... + 897703.

It is an arithmetic number, because the mean of its divisors is an integer number (17055673).

Almost surely, 2^66427321 is an apocalyptic number.

It is an amenable number.

66427321 is a deficient number, since it is larger than the sum of its proper divisors (1795371).

66427321 is a wasteful number, since it uses less digits than its factorization.

66427321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795370.

The product of its digits is 12096, while the sum is 31.

The square root of 66427321 is about 8150.2957615046. The cubic root of 66427321 is about 404.9943016015.

Adding to 66427321 its reverse (12372466), we get a palindrome (78799787).

The spelling of 66427321 in words is "sixty-six million, four hundred twenty-seven thousand, three hundred twenty-one".