730640 has 20 divisors (see below), whose sum is σ = 1698924. Its totient is φ = 292224.

The previous prime is 730637. The next prime is 730663. The reversal of 730640 is 46037.

It can be written as a sum of positive squares in 2 ways, for example, as 430336 + 300304 = 656^2 + 548^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4487 + ... + 4646.

2⁷³⁰⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

730640 is an abundant number, since it is smaller than the sum of its proper divisors (968284).

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

730640 is a wasteful number, since it uses less digits than its factorization.

730640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9146 (or 9140 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 730640 is about 854.7748241496. The cubic root of 730640 is about 90.0674391655.

Adding to 730640 its reverse (46037), we get a palindrome (776677).

The spelling of 730640 in words is "seven hundred thirty thousand, six hundred forty".