66613243 has 4 divisors (see below), whose sum is σ = 66805560. Its totient is φ = 66420928.

The previous prime is 66613229. The next prime is 66613247. The reversal of 66613243 is 34231666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66613243 - 2⁹ = 66612731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66613247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95638 + ... + 96331.

It is an arithmetic number, because the mean of its divisors is an integer number (16701390).

Almost surely, 2^66613243 is an apocalyptic number.

66613243 is a deficient number, since it is larger than the sum of its proper divisors (192317).

66613243 is a wasteful number, since it uses less digits than its factorization.

66613243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192316.

The product of its digits is 15552, while the sum is 31.

The square root of 66613243 is about 8161.6936355146. The cubic root of 66613243 is about 405.3717929161.

The spelling of 66613243 in words is "sixty-six million, six hundred thirteen thousand, two hundred forty-three".