663740 has 48 divisors (see below), whose sum is σ = 1741824. Its totient is φ = 206400.

The previous prime is 663737. The next prime is 663763. The reversal of 663740 is 47366.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1325 + ... + 1755.

It is an arithmetic number, because the mean of its divisors is an integer number (36288).

2⁶⁶³⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870912).

663740 is an abundant number, since it is smaller than the sum of its proper divisors (1078084).

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

663740 is a wasteful number, since it uses less digits than its factorization.

663740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 663740 is about 814.7023996528. The cubic root of 663740 is about 87.2300250111.

The spelling of 663740 in words is "six hundred sixty-three thousand, seven hundred forty".