726631 has 4 divisors (see below), whose sum is σ = 769392. Its totient is φ = 683872.

The previous prime is 726629. The next prime is 726641. The reversal of 726631 is 136627.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136627 = 317 ⋅431.

It is a cyclic number.

It is not a de Polignac number, because 726631 - 2¹ = 726629 is a prime.

It is a super-2 number, since 2×726631² = 1055985220322, which contains 22 as substring.

It is a Duffinian number.

726631 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 726596 and 726605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726601) 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, 21355 + ... + 21388.

It is an arithmetic number, because the mean of its divisors is an integer number (192348).

2⁷²⁶⁶³¹ is an apocalyptic number.

726631 is a deficient number, since it is larger than the sum of its proper divisors (42761).

726631 is a wasteful number, since it uses less digits than its factorization.

726631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42760.

The product of its digits is 1512, while the sum is 25.

The square root of 726631 is about 852.4265364241. The cubic root of 726631 is about 89.9024044943.

The spelling of 726631 in words is "seven hundred twenty-six thousand, six hundred thirty-one".