663665042 has 4 divisors (see below), whose sum is σ = 995497566. Its totient is φ = 331832520.

The previous prime is 663665021. The next prime is 663665059. The reversal of 663665042 is 240566366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 240566366 = 2 ⋅120283183.

It can be written as a sum of positive squares in only one way, i.e., 641659561 + 22005481 = 25331^2 + 4691^2 .

It is a junction number, because it is equal to n+sod(n) for n = 663664987 and 663665005.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165916259 + ... + 165916262.

Almost surely, 2^663665042 is an apocalyptic number.

663665042 is a deficient number, since it is larger than the sum of its proper divisors (331832524).

663665042 is a wasteful number, since it uses less digits than its factorization.

663665042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331832523.

The product of its (nonzero) digits is 155520, while the sum is 38.

The square root of 663665042 is about 25761.6971878795. The cubic root of 663665042 is about 872.2674117784.

The spelling of 663665042 in words is "six hundred sixty-three million, six hundred sixty-five thousand, forty-two".