726821 has 8 divisors (see below), whose sum is σ = 752640. Its totient is φ = 701568.

The previous prime is 726811. The next prime is 726839. The reversal of 726821 is 128627.

726821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-726821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5660 + ... + 5786.

It is an arithmetic number, because the mean of its divisors is an integer number (94080).

2⁷²⁶⁸²¹ is an apocalyptic number.

It is an amenable number.

726821 is a deficient number, since it is larger than the sum of its proper divisors (25819).

726821 is a wasteful number, since it uses less digits than its factorization.

726821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283.

The product of its digits is 1344, while the sum is 26.

The square root of 726821 is about 852.5379756938. The cubic root of 726821 is about 89.9102397267.

It can be divided in two parts, 7268 and 21, that multiplied together give a triangular number (152628 = T₅₅₂).

The spelling of 726821 in words is "seven hundred twenty-six thousand, eight hundred twenty-one".