663649 has 8 divisors (see below), whose sum is σ = 766080. Its totient is φ = 563136.

The previous prime is 663631. The next prime is 663653. The reversal of 663649 is 946366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 663649 - 2¹⁹ = 139361 is a prime.

663649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (663659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 372 + ... + 1210.

It is an arithmetic number, because the mean of its divisors is an integer number (95760).

2⁶⁶³⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

663649 is a deficient number, since it is larger than the sum of its proper divisors (102431).

663649 is a wasteful number, since it uses less digits than its factorization.

663649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959.

The product of its digits is 23328, while the sum is 34.

The square root of 663649 is about 814.6465491242. The cubic root of 663649 is about 87.2260383621.

The spelling of 663649 in words is "six hundred sixty-three thousand, six hundred forty-nine".