663945765 has 16 divisors (see below), whose sum is σ = 1214072448. Its totient is φ = 303518016.

The previous prime is 663945743. The next prime is 663945767. The reversal of 663945765 is 567549366.

It is a happy number.

It is not a de Polignac number, because 663945765 - 2⁶ = 663945701 is a prime.

It is a super-2 number, since 2×663945765² = 881647957722870450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663945767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3161542 + ... + 3161751.

It is an arithmetic number, because the mean of its divisors is an integer number (75879528).

Almost surely, 2^663945765 is an apocalyptic number.

It is an amenable number.

663945765 is a deficient number, since it is larger than the sum of its proper divisors (550126683).

663945765 is a wasteful number, since it uses less digits than its factorization.

663945765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6323308.

The product of its digits is 4082400, while the sum is 51.

The square root of 663945765 is about 25767.1450688663. The cubic root of 663945765 is about 872.3903809431.

The spelling of 663945765 in words is "six hundred sixty-three million, nine hundred forty-five thousand, seven hundred sixty-five".