665636347 has 4 divisors (see below), whose sum is σ = 665843976. Its totient is φ = 665428720.

The previous prime is 665636317. The next prime is 665636393. The reversal of 665636347 is 743636566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 743636566 = 2 ⋅371818283.

It is a cyclic number.

It is not a de Polignac number, because 665636347 - 2¹⁹ = 665112059 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665636297 and 665636306.

It is not an unprimeable number, because it can be changed into a prime (665636317) 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, 98929 + ... + 105442.

It is an arithmetic number, because the mean of its divisors is an integer number (166460994).

Almost surely, 2^665636347 is an apocalyptic number.

665636347 is a deficient number, since it is larger than the sum of its proper divisors (207629).

665636347 is a wasteful number, since it uses less digits than its factorization.

665636347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207628.

The product of its digits is 1632960, while the sum is 46.

The square root of 665636347 is about 25799.9292053292. The cubic root of 665636347 is about 873.1301991312.

The spelling of 665636347 in words is "six hundred sixty-five million, six hundred thirty-six thousand, three hundred forty-seven".