66715243 has 4 divisors (see below), whose sum is σ = 76246000. Its totient is φ = 57184488.

The previous prime is 66715237. The next prime is 66715277. The reversal of 66715243 is 34251766.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66715243 is a prime.

It is a super-3 number, since 3×66715243³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66715199 and 66715208.

It is not an unprimeable number, because it can be changed into a prime (66715343) 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, 4765368 + ... + 4765381.

It is an arithmetic number, because the mean of its divisors is an integer number (19061500).

Almost surely, 2^66715243 is an apocalyptic number.

66715243 is a deficient number, since it is larger than the sum of its proper divisors (9530757).

66715243 is an equidigital number, since it uses as much as digits as its factorization.

66715243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9530756.

The product of its digits is 30240, while the sum is 34.

The square root of 66715243 is about 8167.9399483591. The cubic root of 66715243 is about 405.5785928185.

The spelling of 66715243 in words is "sixty-six million, seven hundred fifteen thousand, two hundred forty-three".