663841 has 4 divisors (see below), whose sum is σ = 698800. Its totient is φ = 628884.

The previous prime is 663827. The next prime is 663853. The reversal of 663841 is 148366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 663841 - 2⁷ = 663713 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663821) 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, 17451 + ... + 17488.

It is an arithmetic number, because the mean of its divisors is an integer number (174700).

2⁶⁶³⁸⁴¹ is an apocalyptic number.

It is an amenable number.

663841 is a deficient number, since it is larger than the sum of its proper divisors (34959).

663841 is a wasteful number, since it uses less digits than its factorization.

663841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34958.

The product of its digits is 3456, while the sum is 28.

The square root of 663841 is about 814.7643831194. The cubic root of 663841 is about 87.2344493266.

The spelling of 663841 in words is "six hundred sixty-three thousand, eight hundred forty-one".