665003640 has 128 divisors (see below), whose sum is σ = 2358720000. Its totient is φ = 146754048.

The previous prime is 665003597. The next prime is 665003681. The reversal of 665003640 is 46300566.

665003640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 665003598 and 665003607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10711 + ... + 38009.

It is an arithmetic number, because the mean of its divisors is an integer number (18427500).

Almost surely, 2^665003640 is an apocalyptic number.

665003640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665003640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1179360000).

665003640 is an abundant number, since it is smaller than the sum of its proper divisors (1693716360).

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

665003640 is a wasteful number, since it uses less digits than its factorization.

665003640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27349 (or 27345 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 665003640 is about 25787.6644929315. The cubic root of 665003640 is about 872.8534660875.

The spelling of 665003640 in words is "six hundred sixty-five million, three thousand, six hundred forty".