663540 has 24 divisors (see below), whose sum is σ = 1858080. Its totient is φ = 176928.

The previous prime is 663539. The next prime is 663541. The reversal of 663540 is 45366.

663540 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (663539) and next prime (663541).

It is a self number, because there is not a number n which added to its sum of digits gives 663540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663541) 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, 5470 + ... + 5589.

It is an arithmetic number, because the mean of its divisors is an integer number (77420).

2⁶⁶³⁵⁴⁰ is an apocalyptic number.

663540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

663540 is an abundant number, since it is smaller than the sum of its proper divisors (1194540).

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

663540 is a wasteful number, since it uses less digits than its factorization.

663540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11071 (or 11069 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 663540 is about 814.5796461980. The cubic root of 663540 is about 87.2212626656.

It can be divided in two parts, 6 and 63540, that added together give a triangular number (63546 = T₃₅₆).

The spelling of 663540 in words is "six hundred sixty-three thousand, five hundred forty".