665655243 has 12 divisors (see below), whose sum is σ = 975561384. Its totient is φ = 403427200.

The previous prime is 665655229. The next prime is 665655257. The reversal of 665655243 is 342556566.

It is an interprime number because it is at equal distance from previous prime (665655229) and next prime (665655257).

It is not a de Polignac number, because 665655243 - 2⁴ = 665655227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665655195 and 665655204.

It is not an unprimeable number, because it can be changed into a prime (665655203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 916518 + ... + 917243.

It is an arithmetic number, because the mean of its divisors is an integer number (81296782).

Almost surely, 2^665655243 is an apocalyptic number.

665655243 is a deficient number, since it is larger than the sum of its proper divisors (309906141).

665655243 is a wasteful number, since it uses less digits than its factorization.

665655243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1833786 (or 1833775 counting only the distinct ones).

The product of its digits is 648000, while the sum is 42.

The square root of 665655243 is about 25800.2954052856. The cubic root of 665655243 is about 873.1384611561.

The spelling of 665655243 in words is "six hundred sixty-five million, six hundred fifty-five thousand, two hundred forty-three".