728623 has 4 divisors (see below), whose sum is σ = 832720. Its totient is φ = 624528.

The previous prime is 728579. The next prime is 728627. The reversal of 728623 is 326827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 326827 = 317 ⋅1031.

It is a cyclic number.

It is not a de Polignac number, because 728623 - 2¹⁷ = 597551 is a prime.

It is a super-2 number, since 2×728623² = 1061782952258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 728591 and 728600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728627) 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, 52038 + ... + 52051.

It is an arithmetic number, because the mean of its divisors is an integer number (208180).

2⁷²⁸⁶²³ is an apocalyptic number.

728623 is a deficient number, since it is larger than the sum of its proper divisors (104097).

728623 is a wasteful number, since it uses less digits than its factorization.

728623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104096.

The product of its digits is 4032, while the sum is 28.

The square root of 728623 is about 853.5941658657. The cubic root of 728623 is about 89.9844829215.

Adding to 728623 its product of digits (4032), we get a triangular number (732655 = T₁₂₁₀).

The spelling of 728623 in words is "seven hundred twenty-eight thousand, six hundred twenty-three".