728690 has 8 divisors (see below), whose sum is σ = 1311660. Its totient is φ = 291472.

The previous prime is 728687. The next prime is 728699. The reversal of 728690 is 96827.

728690 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in 2 ways, for example, as 724201 + 4489 = 851^2 + 67^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×728690² = 1061978232200, which contains 22 as substring.

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (728699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36425 + ... + 36444.

2⁷²⁸⁶⁹⁰ is an apocalyptic number.

728690 is a deficient number, since it is larger than the sum of its proper divisors (582970).

728690 is a wasteful number, since it uses less digits than its factorization.

728690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72876.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 728690 is about 853.6334107801. The cubic root of 728690 is about 89.9872409896.

The spelling of 728690 in words is "seven hundred twenty-eight thousand, six hundred ninety".