663739 has 4 divisors (see below), whose sum is σ = 665856. Its totient is φ = 661624.

The previous prime is 663737. The next prime is 663763. The reversal of 663739 is 937366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 937366 = 2 ⋅468683.

It is a cyclic number.

It is not a de Polignac number, because 663739 - 2¹ = 663737 is a prime.

It is a super-3 number, since 3×663739³ = 877229574333757257, which contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663737) 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, 484 + ... + 1249.

It is an arithmetic number, because the mean of its divisors is an integer number (166464).

2⁶⁶³⁷³⁹ is an apocalyptic number.

663739 is a deficient number, since it is larger than the sum of its proper divisors (2117).

663739 is a wasteful number, since it uses less digits than its factorization.

663739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116.

The product of its digits is 20412, while the sum is 34.

The square root of 663739 is about 814.7017859315. The cubic root of 663739 is about 87.2299812037.

The spelling of 663739 in words is "six hundred sixty-three thousand, seven hundred thirty-nine".