665061563 has 4 divisors (see below), whose sum is σ = 666080688. Its totient is φ = 664042440.

The previous prime is 665061493. The next prime is 665061581. The reversal of 665061563 is 365160566.

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 665061563 - 2¹⁴ = 665045179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665061863) 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, 508583 + ... + 509888.

It is an arithmetic number, because the mean of its divisors is an integer number (166520172).

Almost surely, 2^665061563 is an apocalyptic number.

665061563 is a deficient number, since it is larger than the sum of its proper divisors (1019125).

665061563 is a wasteful number, since it uses less digits than its factorization.

665061563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019124.

The product of its (nonzero) digits is 97200, while the sum is 38.

The square root of 665061563 is about 25788.7875442022. The cubic root of 665061563 is about 872.8788077150.

The spelling of 665061563 in words is "six hundred sixty-five million, sixty-one thousand, five hundred sixty-three".