66370813 has 4 divisors (see below), whose sum is σ = 66401440. Its totient is φ = 66340188.

The previous prime is 66370807. The next prime is 66370877. The reversal of 66370813 is 31807366.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31807366 = 2 ⋅15903683.

It is a cyclic number.

It is not a de Polignac number, because 66370813 - 2⁹ = 66370301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66370313) 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, 11793 + ... + 16486.

It is an arithmetic number, because the mean of its divisors is an integer number (16600360).

Almost surely, 2^66370813 is an apocalyptic number.

It is an amenable number.

66370813 is a deficient number, since it is larger than the sum of its proper divisors (30627).

66370813 is a wasteful number, since it uses less digits than its factorization.

66370813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30626.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 66370813 is about 8146.8284012860. The cubic root of 66370813 is about 404.8794296378.

The spelling of 66370813 in words is "sixty-six million, three hundred seventy thousand, eight hundred thirteen".