663913 has 4 divisors (see below), whose sum is σ = 680148. Its totient is φ = 647680.

The previous prime is 663907. The next prime is 663937. The reversal of 663913 is 319366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 319366 = 2 ⋅159683.

It can be written as a sum of positive squares in 2 ways, for example, as 363609 + 300304 = 603^2 + 548^2 .

It is a cyclic number.

It is not a de Polignac number, because 663913 - 2⁵ = 663881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663973) 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, 8056 + ... + 8137.

It is an arithmetic number, because the mean of its divisors is an integer number (170037).

2⁶⁶³⁹¹³ is an apocalyptic number.

It is an amenable number.

663913 is a deficient number, since it is larger than the sum of its proper divisors (16235).

663913 is a wasteful number, since it uses less digits than its factorization.

663913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16234.

The product of its digits is 2916, while the sum is 28.

The square root of 663913 is about 814.8085664744. The cubic root of 663913 is about 87.2376030202.

The spelling of 663913 in words is "six hundred sixty-three thousand, nine hundred thirteen".