728669 has 4 divisors (see below), whose sum is σ = 767040. Its totient is φ = 690300.

The previous prime is 728659. The next prime is 728681. The reversal of 728669 is 966827.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 966827 = 733 ⋅1319.

It is a cyclic number.

It is not a de Polignac number, because 728669 - 2¹² = 724573 is a prime.

It is a super-2 number, since 2×728669² = 1061917023122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19157 + ... + 19194.

It is an arithmetic number, because the mean of its divisors is an integer number (191760).

2⁷²⁸⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

728669 is a deficient number, since it is larger than the sum of its proper divisors (38371).

728669 is a wasteful number, since it uses less digits than its factorization.

728669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38370.

The product of its digits is 36288, while the sum is 38.

The square root of 728669 is about 853.6211103294. The cubic root of 728669 is about 89.9863765387.

The spelling of 728669 in words is "seven hundred twenty-eight thousand, six hundred sixty-nine".