663690 has 16 divisors (see below), whose sum is σ = 1592928. Its totient is φ = 176976.

The previous prime is 663683. The next prime is 663709. The reversal of 663690 is 96366.

663690 is nontrivially palindromic in base 4.

It is a super-2 number, since 2×663690² = 880968832200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 22123 = 663690 / (6 + 6 + 3 + 6 + 9 + 0).

It is an unprimeable number.

663690 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11032 + ... + 11091.

It is an arithmetic number, because the mean of its divisors is an integer number (99558).

2⁶⁶³⁶⁹⁰ is an apocalyptic number.

663690 is an abundant number, since it is smaller than the sum of its proper divisors (929238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

663690 is a wasteful number, since it uses less digits than its factorization.

663690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22133.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 663690 is about 814.6717130231. The cubic root of 663690 is about 87.2278345897.

The spelling of 663690 in words is "six hundred sixty-three thousand, six hundred ninety".